SWIG Improvements

*) Extend SWIG support deeper into the BOARD class.
*) Move swig *.i files into a directory identified for SWIG, in preparation
   for a parallel universe involving Phoenix's SIP.
*) Move swig files which will be common to both eeschema and pcbnew into
   common/swig.
*) Sketch out a "common" python module, and plan on dovetailing that into a
   libkicad_shared.{dll,so}
*) Add common/swig/ki_exceptions.i and define a macro HANDLE_EXCEPTIONS()
   which is to be applied to any function which needs C++ to python
   exception translation.
*) Move the test for SWIG tool into top level CMakeLists.txt file for use
   in all python modules beyond pcbnew, i.e. eeschema and common.
*) Add SWIG_MODULE_pcbnew_EXTRA_DEPS which generates a better Makefile, one
   which rebuilds the swig generated *.cxx file when one of its dependencies
   change.
*) Re-architect the board.i file so that it can be split into multiple *.i
   files easily.
*) Make some KIWAY from python progress, in preparation for Modular KiCad
   phase III.

pcbnew/python/examples/listPcbLibrary.py

@@ -0,0 +1,12 @@
+#!/usr/bin/env python
+from pcbnew import *
+
+lst = FootprintEnumerate("/usr/share/kicad/modules/sockets.mod")
+
+for name in lst:
+    m = FootprintLoad("/usr/share/kicad/modules/sockets.mod",name)
+    print name,"->",m.GetLibRef(), m.GetReference()
+
+    for p in m.Pads():
+        print "\t",p.GetPadName(),p.GetPosition(),p.GetPos0(), p.GetOffset()
+