remove footer under spritelist

in the new mockup the clickable footer is removed under list of sprites
remove footer under projectlist

in the new mockup the clickable footer is removed under list of projects
quickfix for IllegalStateException

could happen that Activity is loaded but Fragment is still missing.
this could lead to IllegalStateException when adding a new Sprite
remove unused strings

contentDescriptions for removed footerimages not needed any more
quickfix for jenkins

IllegalstateException occurred several times on jenkins.
this could solve the problem
Merge branch 'master' into ExploringIllegalStateException
Merge pull request #134 from Catrobat/ExploringIllegalStateException

quickfix for IllegalStateException on Jenkins