Adjustments to syncsource.py.

- renamed sync-source.py to syncsource.py to appease pylint.
- added missing lib/transfer/__init__.py file.  Fumble from
  git to svn.
- adjusted README to call sync-source.py syncsource.py, and
  call .sync-sourcerc .syncsourcerc.
- marked syncsource.py as executable by all.

llvm-svn: 247922