fixed issues #910, #909 and #906

Feature_Backpack_Enabled can be set in build.gradle

changed the strings accordingly

removed checkstyle warning

added check if BuildConfig.FEATURE_BACKPACK_ENABLED is true

fixed TODO
add tasks to switch to old branches
Merge pull request #915 from Catrobat/issues910_909_906

fixes [CAT-917]
fixed issues #910, #909 and #906
Merge pull request #1029 from Catrobat/switchToOldBranches

add tasks to switch to old branches
Disable preDex step for jenkins builds
Also switch from jenkins task to jenkins property
Merge pull request #1030 from Catrobat/disablePreDexForJenkins

Disable preDex step for jenkins builds
bricks, utils and layouts copied

modified files that could cause merge conflicts

testclasses copied

bugfix - wrong bitmask used

removed unused variable

trying to suppress hardcoded ip waring, using //nopmd

removed sprite parameter from led action

pull request #996 comments

refactoring conding std

conding std fixes for pull request #996

lint warning

surfacetexture changed to be compatible for sdk 11+

fixed import orders

targetapi fix
Merge pull request #996 from Catrobat/vibration_and_led_brick

Vibration and led brick
Update CHANGELOG.md
fixed issue cat-780

fixed behaviour except android-back-button

adapted tests