Coding policy fixes and dialog design rules cosmetic enhancement.

gr_basic.cpp: fix a bug I created in my last commit. Pcbnew: fix a very minor bug in hight light behavior

gr_basic: fix incorrect clipping of thick lines (due to changes in code, the thickness was not taken in account to calculate the clip box size)
Pcbnew: fix a very minor bug.

gr_basic: fix incorrect clipping of thick lines (due to changes in code, the thickness was not taken in account to calculate the clip box size)

Made symbol text capable of overlining. Format for text is slightly changed: now text with quotes and/or tildes saved in quoted format: it will cause libraries to fail loading in older versions when ~s or "s are used in text.

* Change class WinEDA_MsgPanel name to EDA_MSG_PANEL per coding policy.
* Change some old set message panel code in PCBNew with updated message
  panel methods in EDA_DRAW_FRAME.
* Remove unused global function Affiche_1_Parametre.
* Minor Doxygen warning fixes.

Also fix a minor zoom page issue in Libedit.
wxMSW, version 2.8.x must be patched.
Some zoom values smaller than 3 to 5 create artifacts on screen, mainly values < 1.
(corresponding to draw scale factor > 1 )

 * see http://trac.wxwidgets.org/ticket/9554
 
This is fixed in version 2.9.x
Workaround: ( that is not a full fix, but remaining artifacts are acceptable )
edit file  edit file <wxWidgets>/src/msw/dc.cpp
 >> search for line
    static const int VIEWPORT_EXTENT = 1000;
 >> and replace by
    static const int VIEWPORT_EXTENT = 10000;

Eeschema: bug fix: incorrect behavior when changing(for a multiple parts per package component) the selected part (component not deselected)
Fix a minor compil warning in lib_polyline.cpp

CMake: add definition KICAD_TESTING_VERSION and KICAD_STABLE_VERSION.
One of these 2 options *must* be now defined (i.e. run cmake with option -DKICAD_STABLE_VERSION or -DKICAD_TESTING_VERSION
Stable and testing branches should be more easier to maintain.

Pcbnew: Try to fix MacOSX crash when loading a file at start time by removing a useless call to wxSafeYield() in load file function.
Eeschema: Calling Viewlib to load a component uses now MakeModal() instead of wxFRAME_FLOAT_ON_PARENT (better behavior, like a dialog).

* Component moves can now be undone do to incorrect virtual method declaration
  in schematic component object.
* Undoing a field move now redraws the undone field properly.
* Fix bug when after aborting a field move kept displaying context menu
  field items.
* Removed unused current field member variable and access methods from the
  schematic edit frame object.
* Update component move code to comply with coding policy.

In Render, colors shown were the default colors, not the selected colors, when starting Pcbnew or Gerbview,
because colors were not updated after reading the config.

All: fix a very minor issue: when a window is closed mazimized, and later reopened, it was not maximized. But this is very annoying when using 2 monitors with a different size
Very minor other enhancements and fixes

* Merged CMake 2.8.4 version of FindwxWidgets.cmake with local copy.
* Merged CMake 2.8.4 version of UsewxWidgets.cmake with local copy.
* Bump required version of CMake to 2.8.0.
* Delete commented out include from eeschema/protos.h that I forgot on my
  last commit.

All: fix a very minor issue: when a window is closed mazimized, and later reopened, it was not maximized.

fix an issue created by commit 2954. Gerbview: display now an indicator of layers in use. minor code cleanup.

* Move undo item copy global variable into schematic editor frame object
  member variable.
* Add helper methods for accessing the undo item copy member variable.
* Fix undetected bug when changing a text type.
* Added an exchange command to the undo/redo base class for handling undoing
  a changed item type which cannot be undone by swapping out the variables.
* Revert change to common/hotkeys_basic.cpp that broke hot key behavior.
* Lots of coding policy changes while making the changes above.

* Gerbview, Pcbnew: add SetLocaleTo_Default() after reading double in config to fix issues with decimal separator (when the separator is not a point).
(WxWidgets 2.9.1 seems call setlocale( LC_NUMERIC, "" ) when wxConfig read doubles stored in config, but forget to back to current locale.)
Note: perhaps there are some dialogs that need this call to  SetLocaleTo_Default() ).
* Minor  code cleanup in pcbnew/netlist.cpp

* store selected language by name instead of wx language id (that changes between wxWidgets version)
* accept always comma and point as flotating point separator.

* VERTEX INSERT: when dragging middle of a edge a new vertex is added there;
* VERTEX DELETE: when dragging vertex onto its neighbour vertex  they're collapsed into one.

* will not add zero-length segments when creating polylines;
* polyline vertex to edit is now being chosen correctly.

* Fixed minor code formatting issues with submitted patch.
* Change field name to "spice_model" per discussion with Charles McDowell.