Pcbnew: 2 minor enhancements

Pcbnew: fix issue when KICAD_NANOMETER is defined: when zones use htcth to show zones areas, hatch lines were incorrectly calculated (hunded of thousand lines created)
Eeschema: fix issue in search: search not made in reference strings.
Minor fixes, code cleaning and comment enhancements.

This feature is very useful for electronics hobbyists who use DIY PCB technology 
(both toner transfer and photoresist methods).
Also width correction may be useful for PCB designers who take care of track width etching.
This patch also fixes some minor PS plotting issues.

Minor other enhancements and code cleaning.

* EDA_DRAW_PANEL completely encapsulated.
* Moved OSX m_overlay member from EDA_DRAW_PANEL to EDA_DRAW_FRAME where
  it is used.
* Doxygen comment warning fixes.

* EDA_DRAW_FRAME completely encapsulated.
* Encapsulate the the low hanging fruit in EDA_DRAW_PANEL.

* EDA_RECT and EDA_ITEM completely encapsulated.
* Removed unnecessary EDA_ITEM member m_Selected and replaced functionality
  with SELECTED flag bit.

* EDA_DRAW_FRAME completely encapsulated except for DrawFrame member.
* Moved members specific to Pcbnew from EDA_DRAW_FRAME to PCB_BASE_FRAME
  or PCB_EDIT_FRAME as appropriate.
* Replace EDA_TOOLBAR with wxAuiToolBar as EDA_TOOL bar provided no
  additional functionality and made code less readable.
* Remove EDA_TOOLBAR class definition from wxstruct.h and delete file
  wineda_toolbar.cpp.
* Rename tool bar members to something more descriptive since the
  horizontal and vertical references wont mean anything once the
  tool bars are movable.
* Lots of dead code removal.

In common.cpp GetTimeStamp is renamed GetNewTimeStamp (a better name).
Pcbnew: prepare work to calculate connections between pads that inteserct and therefore can be connected without any track (composite pads).

  * Removed Pcb_Frame argument from BOARD() constructor, since it precludes
    having a BOARD being edited by more than one editor, it was a bad design.
    And this meant removing m_PcbFrame from BOARD.
  * removed BOARD::SetWindowFrame(), and BOARD::m_PcbFrame
  * Removed the global BOARD_DESIGN_SETTINGS which was in class_board.cpp
  * added BOARD_DESIGN_SETTINGS to the BOARD class, a full instance
  * a couple dialogs now only change BOARD_DESIGN_SETTINGS when OK is pressed,
    such as dialog_mask_clearance, dialog_drc, etc.
  * Removed common/pcbcommon.cpp's int g_CurrentVersionPCB = 1 and replaced it
    with build_version.h's #define BOARD_FILE_VERSION, although there may be a
    better place for this constant.
  * Made the public functions in PARAM_CFG_ARRAY be type const.
    void SaveParam(..) const and void ReadParam(..) const
  * PARAM_CFG_BASE now has virtual destructor since we have various way of
    destroying the derived class and boost::ptr_vector must be told about this.
  * Pass const PARAM_CFG_ARRAY& instead of PARAM_CFG_ARRAY so that we can use
    an automatic PARAM_CFG_ARRAY which is on the stack.\
  * PCB_EDIT_FRAME::GetProjectFileParameters() may no longer cache the array,
    since it has to access the current BOARD and the BOARD can change.
    Remember BOARD_DESIGN_SETTINGS are now in the BOARD.
  * Made the m_BoundingBox member private, this was a brutally hard task,
    and indicative of the lack of commitment to accessors and object oriented
    design on the part of KiCad developers.  We must do better.
    Added BOARD::GetBoundingBox, SetBoundingBox(), ComputeBoundingBox().
  * Added PCB_BASE_FRAME::GetBoardBoundingBox() which calls BOARD::ComputeBoundingBox()

Eeschema: fix crash in intermediate netlist generation when a component has no pins (like logos or images).
Pcbnew: texts in dimensions can be now moved.
Gerbview: fix incorrect number of layers  in export to pcbnew function.

Some code restyling: VECTOR_PCB is an array. Cleanup uncontrolled definitions of abs, max, etc. max is now overloaded function and MAX is a macro.

Metric KiCad work continues. Partially processed D_PAD class. It is still need to be tested including all these import and export procedures...

General design rules tab converted to nanoscale. A bit of refactorisation in via sizes. And build key is KICAD_NANOMETRE not KICAD_NANOMETRIC (as I stated in previous commit).

Added configuartion option KICAD_NANOMETRIC for this.
* With option set to false: *
- it should work and compile as usual
- some values are saved with decimal point (which should be backward/forward compatible as old versions should just drop fractional part)
* With option set to true: *
- lengths in Global Design Rules should be settable 1nm steps.
FROM/TO_LEGACY_LU(_DBL) macros introduced for easy interconnection between old and new units.

More work about code refactoring in connect.cpp

* Grammar and spelling fixes in Eeschema, CvPcb, and Pcbnew path and
  library dialog tool tips.
* Translate the French file name subrill.cpp to highlight.cpp.
* Lots of coding style policy fixes.

* Factor auto save common code into base frame class so all frame windows
  can take advantage of the shiny new auto save goodness.
* Use a timer instead of depending on mouse and keyboard events to trigger
  an auto save.
* Check for auto save file when opening a board and ask user if they
  wish to use the auto save file or the last saved board file.
* Protect all base frame public members.