fixed minor problems and fixed Layer Alignment Target bug.

* Remove redundant background redrawing RedrawActiveWindow.
* Remove redundant managed cursor callback in RedrawActiveWindow.
* Use refresh to redraw instead of directly calling RedrawActiveWindow.
* Remove unused SetDrawBgColor for drawframe.cpp.
* Fix compiler warning in cvpcb/cvframe.cpp.
* Fix menu spelling and syntax errors in pcbnew.
* Rename Trace_Curseur to DrawCursor in common/drawpanel.cpp.

Code cleaning.
Patch for 3D problem with macOSX

files cleaning

fixed a grid refresh problem when using fast algo in drawpanel.cpp

Added patch for macOSX
turn on fast algo for draw grid (should work now)

Fast algo currently disabled (tests needed)

Ugly but necessary fix to display toolbars in latest Linux version (tested with Ubuntu 9.10 updated)

Fixed others minor problems 

    constructor takes a keyword table, so it can be used for arbitrary DSN
    syntax files of your own chosing.  Simply create an enum {} with all your
    unique tokens in it.  Then create a KEYWORD table.  See SPECCTRA_DB::keywords[].
    The reason you want an enum is to give the C++ debugger better type information
    so it can show symbolic integer symbols.
  * Factored out common richio.cpp and richio.h
    which is what DSNLEXER uses.
  * Fixed some minor issues with reading circuit descriptor from a *.dsn file.

  * Moved ReturnLayerName() to static BOARD::GetDefaultLayerName() and migrated
    to a Specctra DSN compatible default layer naming scheme:
        Component becomes Front, Copper becomes Back.
  * set_color.h: Cmp becomes Front, Cu becomes Back.
  * D_PAD::DisplayInfo() changed to use actual copper layer names.
  * more layer setup dialog work, moved all programmatic wxControl instantiation
    into the wxFormbuilder environment, but this is fraught with danger:
    wxFlexGridSizer used the tallest control to establish the row heights, so
    be careful about changing control borders in the scroll panel. The vertical
    size can explode since just a couple of pixels times the number of rows
    is substantial.  Currently I am setting a 5 pixel border only left, top, and right
    but not bottom.
  * Set copper layer count is back in place as a hack until I can get the enabled
    layer bit map fully operational.

* Fixed EESchema options dialog focus bug so escape key now works in GTK.
* Rename schematic objects for improved readability.
* Fixed GCC compiler warnings in plot code.
* Added paragraph in UIpolicies.txt about setting dialog box sizes.
* Lots of message box string clean up.