hotfix for image selection for 4.4. kitkat devices.
Intent changed to ACTION_PICK same as in new object workflow.

ACTION_PICK is still working fine on 4.4 devices.
Merge pull request #847 from Catrobat/issue#825hotfix

Hotfix for image selection for 4.4. kitkat devices. On 4.4 devices picking pictures from "Downloads" or "Google Drive" in the Dialog opened by an ACTION_GET_CONTENT intent return different references. Further work needed.

info for issue #846: now it's using the same intent, but still a different layout.
Maximize/Stretch logic now works in stage
xml tag added to remember the screenMode setting
test to check remembering of screen mode
new function getScreenMode()
and used the enum to get the strings
fixed test
needs longer sleep time, otherwise a NullPointerException happens
added errormasseges to tescase
refectoring
fix saveScreenshot after Maximize/Stretch
"Streched" is now the standart view in the stage.
Merge pull request #730 from Catrobat/MaximizeStretch

save ScreenMode in XmlHeader
fix streching of stage when Aspect radio is the same but display resolution isn't

refector screenMode enum
fix wrong position of click events in Stage wenn Streched.
improve Stage.
refector stage
fix test
add new regression test
Testexclusion support for new jenkins paralell test plugin
Merge pull request #855 from Catrobat/testexclusions_pr

Testexclusion support for new jenkins paralell test plugin
refectoring
Merge pull request #852 from Catrobat/MaximizeStretchV2

Maximize/Stretch code improvements
Merge branch 'master' into DatatypeString