Enable kernel stack in SAMA5D4-EK knsh configurations
examples/null/null_main.c:  Need to include config.h it order know if this is or is not a kernel build
Update README
Move some share-able logic from sama5/sam_pgalloc.c to armv7-a/arm_physpgaddr.c
Move some share-able logic from sama5/sam_pgalloc.c to armv7-a/arm_physpgaddr.c
Move some share-able logic from sama5/sam_pgalloc.c to armv7-a/arm_physpgaddr.c
Correct stack handling is signal deliver to user processes
Move common/up_signal_dispatch.c to armv6-m, armv7-m, and armv7-a.  The armv7-a version needs to be different to handle the case where we are dispatch kernel mode signals when running under a user mode group
remove tailing blank line
These files were deleted and moved to a different location (see previos commit)
Update ChangeLogs
Update TODO and a README
First round of changes to get the ELF configuration building again
A couple more changes for clean ELF build
More changes so that the KNSH build survives the changes needed for the ELF build
Eliminate some nshlib warngings
Update README
Add a sharable version of arm_virtpgaddr()
Fix errors in apps/examplex/helloxx and cxxtext Makefiles; update SAMA5D3x-EK/hello defconfig
Only SAM4 family has RTTDIS bit in the MR register. SourceForge bug #33 from Fabien Comte