Standalone: Fix for virtualenv and site module. Fix for Issue#126.

* Make sure precompiled files are compiled to bytecode from source
  where possible. This will be good against outdated ".pyc" files
  that are otherwise used.

* For "site" module, make sure to set "__file__" to a path where
  the binary lives.

* Put the potential data file of "site" module into the dist dir
  as well.
New hotfix release.
Merge branch 'hotfix/0.5.1.2'
Merge tag '0.5.1.2' into develop
New pre-release.