NOTEPAD-8 UPDATE A NOTE
- made list of notes clickable
- opens input screen and show the NoteFragment with the respective title
  and description of the entry on a click
- detects if note is edited
- updates entry in the database
- checks if edited title allready exists
- checks if title or description is empty after editing
- created showCreate() and showUpdateNote() method in main activity
- fixed variable name in NoteInputFragment
NOTEPAD-9
- created context menu
- deleted some whitespaces
Merge branch 'NOTEPAD-9' of github.com:Daniel-enough/notepad into NOTEPAD-9

Conflicts:
	src/de/enough/notepad/fragment/NoteListFragment.java
NOTEPAD-9
- fixed merge errors