Add board support infrastructure for the pcDuino board.  There is not much there on the initial checkin

Add framework for Spark Core board support.  The initial commit is a clone of the Maple Mini and still needs Spark customizations

Upate .gitignore files.  Add .dSYM. Make sure / is present where needed.  Add some missing .gitignore files

Converted configs/pcblogic-pic32mx configurations to use kconfig-frontends.  Re-organization of files in configs/pcblogic-pic32mx/src

Fix comments, references to the old SVN, and links to the old SVN.  Replace with equivalent GIT info

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5673 42af7a65-404d-4744-a932-0658087f49c3

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5664 42af7a65-404d-4744-a932-0658087f49c3

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5592 42af7a65-404d-4744-a932-0658087f49c3

Misc clean; mark assertions as non-returning; allow toolchain prefix to be overriden from make command line

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5591 42af7a65-404d-4744-a932-0658087f49c3

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5577 42af7a65-404d-4744-a932-0658087f49c3

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5574 42af7a65-404d-4744-a932-0658087f49c3