optimize hash code and move get_hash to get_version & get_sys_info
update CHANGES.md
Update CHANGES.md
debian packaging
Merge branch 'debian' into developing
update debian
debian update
Fix for Android subject number
Fix
update make
Merge remote-tracking branch 'origin/android_subject_fix' into developing

Conflicts:
	expyriment/control/_experiment_control.py
Minor docu fix
Update CHANGES.md
Update CHANGES.md
Minor changes
Merge pull request #20 from expyriment/developing

Developing