NXDRIVE-40: Allow to not remove esky freeze output directory after zipping it
NXDRIVE-40: Zip esky freeze by default and don't remove freeze directory afterwards (to be able to use it as a base for the MSI package)
NXDRIVE-40: Fix boolean options badly handled
NXDRIVE-40: Don't create zip file from esky freeze under OS X (seems to not embed all files from the bundle, eg. PyQt Framework stuff...)
NXDRIVE-40: Improve and comment DMG creation script
NXDRIVE-40: Zip application bundle after creating DMG to make it available as an update
Merge branch 'feature-NXDRIVE-40-release-process'