fixed Problem with deleted project in Settings:
 - project now gets also deleted from settings
 - added tests
 - refactored testDeleteSprite and testDeleteViaActionBar
 - some minor changes
Merge pull request #1130 from Catrobat/refactor_deleteProject

fixed Problem with project in Settings
CAT-1174 #fixed
Update README.md

extent contribute section
* Implementation of core functionality
* User list fragment added
* Brick category data introduced
* Add item to user list
* Get item of list implemented
* Length of list implemented
* Function contains implemented
* Delete item of user list brick
* Insert item to user list
* Insert item into userlist brick, replace item in userlist brick
* New Design of Lists and Variables in FE
* FE DataAdapter refactored
* list bricks refactoring
* Fixed language version support
* Renamed data XML-tag to xdata, to avoid XSTREAM errors
* Fixed language version support for variables
* Keyboard layout fixed
* Fixed import order
* Fixed Null Pointer Error
* UserListAdapter list items view refactored
* Typos fixed
* Data dialog layout refactored
* Function contains display fix
* XML format refactored
* Default brick values fixed for data bricks, XML newlines removed, variable dialog typo fixed
* Toogle mindstorm bricks test fixed
* Index parameters in list bricks are now integers
* Function contains display errors fixed
* Number of elements function added
* Formula element interpreation changed
* Renamed xml tag xdata to data
* Introduced project field sorter