Remove executable bit from CHANGELOG, LICENSE and README in the bundles

in the README (Bitmask-linux64-0.3.0), the user should run "./launcher" i myself got confused, tried apps/launcher.py

please updated the README to include that the user should run './bitmask'

btw: CHANGELOG, LICENSE and README should not have the executable bit set

(from redmine: created on 2013-08-29, closed on 2013-09-09)