Support for the older, manual configurations has been completely removed from the NuttX build system

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