[MacOSX] Treats LLVM as GCC + adds support for boost multiple processor(ppc/intel) and address(32/64 bit)

Pcbnew:, libedit, Save lib as...: the new .pretty lib format is the default, instead of legacy .mod format. The legacy format is still selectable in the file selection dialog.

* Change general properties dialog to allow for entry of arbitrary rotation
  angles for greater than 0 to 90.
* Move global rotation angle variable into PCB_EDIT_FRAME object where it is
  used and add accessors.
* Change rotate footprint undo operation from UR_ROTATE_XXXX to UR_CHANGE.
* Create function to remove trailing zeros from floating point wxString
  objects.

Minor change: Eeschema+Pcbnew: display timestamp in edit dialogs (for footprints, sheets, components)

* Make GPCB_PLUGIN::EnumerateFootprints() read the directory contents
  instead of loading the entire cache.
* Make KICAD_PLUGIN::EnumerateFootprints() read the directory contents
  instead of loading the entire cache.

* Make GPCB_PLUGIN::EnumerateFootprints() read the directory contents
  instead of loading the entire cache.
* Make KICAD_PLUGIN::EnumerateFootprints() read the directory contents
  instead of loading the entire cache.

kicad-install.sh and library-repos-install.sh utilize /etc/profile.d/kicad.sh for setting environment variables globally

* Prevent cache from being reloaded on every footprint file read.
* Fix a bug forming wxFileName in GPCB_FP_CACHE::Load().
* Fix invalid file name time stamp debug assertion.
* Use FPID to set loaded footprint name.
* Remove file name <> from exception strings per UIPolicy.

move ${Boost_LIBRARIES} into cvpcb, pcbnew, _pcbnew and out of github, because worker threads used regardless of github

   To use multiple working threads.  This entailed adding KiCad typedefs:
*) Add typedefs for MUTEX and MUTLOCK which mask the actual choices for the project.
*) Add FOOTPRINT_LIST::DisplayErrors( wxWindow* ) which is a single strategy for
   showing aggregated load errors.  Although what's there is only scaffolding
   and needs a volunteer who knows HTML pretty well.
*) Ensure all callers of ReadFootprintFiles() use the new DisplayErrors() function.   
*) Push utf8.cpp and utf8.h into common library for open use.