Load with cFE 6.4.0

MODIFICATIONS:
  * Add empty .gitignore files to otherwise empty directories
  * Carry the older "readme" files forward
  * Copy the new cfe-OSS-readme.txt to cfe-6.4.0-OSS-readme.txt
Merge tag '6.4.0' into development
Update Readme.md to match text of cfe-6.4.0-OSS-readme.txt
Goddard 6.4.0 Update 2014-10-07

Changes to some Makefiles in the build tree.
Version number not changed.
Merge '6.4.0' update into development
Merge branch 'development'