Correct executable bit for source files

Many media files and source code files were marked as executable in Git.
Remove those.

Also a shell script and python script were not marked as executable.

Change-Id: Ieb51bafb46c895a21d2e83696f5a901ba752b2c5
base: cleanup duplicate sound files

http://jira.omnirom.org/browse/OMNI-56
http://jira.omnirom.org/browse/OMNI-262

Change-Id: I42b39ed18864abbb5fddcd099446d766e1961439