Correctly start Pocket Paint or Paintroid, depending on our build

Depending on the build (release or debug) either a debug version of Paintdroid (debug) or the store version of Pocket Paint is offered as download. The download is only offered if there is no version of Pocket Paint or Paintdroid installed.

- added download of debug version of Paintdroid to checkIfPocketPaintIsInstalled() in LookFragment.

- added POCKET_PAINT_DOWNLOAD_LINK_NIGHTLY to constants.
When copying a brick from context dialog the new brick is inserted at the position of the old one
Optimized Layouts & emptyView implementation

* Removed unnecessary overdraw where possible
* Added the correct handling of empty ListViews for Scripts, Looks,
  Sounds.
* Fix tests that failed after removal of ListView
* Deleted FtpProgressInputStream
* Remove "fix" in UiTestUtils
Merge pull request #669 from Catrobat/layout_optimization

Optimized Layouts & emptyView implementation
move text in soundRecorder below button
Merge pull request #667 from Catrobat/CopyBrickIssue

Copy brick issue
Merge pull request #666 from Catrobat/issue#586

Correctly start Pocket Paint or Paintroid, depending on our build
add lint.xml files to Android project folders

in order to be able to check lint warnings with our config,
lint.xml files are introduced with ignored checks.
- add lint.xml files (they were located in our jenkins repo)
- remove them from .gitignore
- move ignore logic in testprojects from Manifest to lint.xml
- comment tools:ignore in .xml files
- ignore NewApi warning for textAllCaps - is just capitalized
on Android 2.3.x
- ignore Icon Density warning - icons will be provided by UI team,
and warning will be activated again
Merge pull request #672 from Catrobat/introduceLint

introduce lint
Change index
Merge pull request #673 from Catrobat/FixTestCopyFromContextDialog

Fix testCopyFromContextDialog
Bottom bar hidden on action mode

Fixes #641
The BottomBar is now hidden everywhere where it is not intended to be,
like renaming/deleting objects (instead of disabling the buttons in the
Bottombar).
Also the BottomBar.java class has changed. Now there are methods for
showing and hiding the BottomBar and the Add+Play - Button.
The Bottombar separator is now handled automatically by BottomBar.java
(was: setting separator visibility manually where it was needed).

Jenkins Testrun(s):
https://jenkins.catrob.at/job/Catroid-Multi-Job-Custom-Branch/355/

Ran the failed ui test separatly 10 times:
https://jenkins.catrob.at/view/Catroid/job/Catroid-single-UI-emulator/183/
Merge pull request #663 from Catrobat/issue#641

Issue#641
Merge pull request #671 from Catrobat/issue#651

fix issue#651
Fixes #646

test fixed
Merge pull request #675 from Catrobat/issue#646

Fixes #646
Merge branch 'master' into SOR-facedetection
issue SOR-3 correct behaviour if camera not available