Fix bug 910364: When a footprint saved in a .mod file is not on front layer and/or not with orientation 0 degree, the Module editor load it incorrectly.
note:  the Module editor save it with default orientation and layer, but the archive function does not, so some footprints can be not editable.
TODO: modify the Archive Function to use the default layer / orientation.

Pcbnew: fix a very minor issue.

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.

size while routing (W, Ctrl+W) didn't update the track in the display
window (you had to move the mouse to get a refresh).

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

Better code in test connections in zones.
Very minor other fixes

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

* A track is seen connected to a pad if the track end is inside the pad shape.
* Pads inside pads are now seen connected, if the center of the pad is *inside* the other pad.
* this is made to be sure a large copper area is shared by the 2 pads,  and to keep algorithm fast.

Minor cosmetic enhancements.
Pcbnew: more workd abput connection algorithms (work in progress)

* 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.

KICAD_PLUGIN::Load() is solid now, except for missing globals, which
still need to get moved into the class BOARD.

Same for KICAD_PLUGIN::Save(), only missing globals, which once they
are in the BOARD class, will be added.

Pcbnew: fix issue when creating new tracks: sometimes a ratsnest remains active although a track exists.

Pcbnew: fix bad initialization of default track width and vias sizes when starting pcbnew with no board loaded.