Adds Confirmation popups for duplicate files errors

- ProjectManager: renaming a file to a name that already exists
- ProjectManager: moving a file into a folder with a file that has the same name
- Refactor->Rename: when renaming a type leads to a file rename, and that file already exists
Refactor->Rename: don't reload renamed files
ASCompletion: rewrote "Add Closing Braces", closes #357
Fix closing braces in string interpolation expressions
Support {} braces, don't duplicate closing braces when there already is one
Fix indent on newline on while in {}-braces caused by smart-indent, some cleanup
Update docs of  "Add Closing Braces"
Some shortcut improvements

- added shortcuts for focus of the debug / release and target selection combo boxes
- added a shortcut to toggle release / debug mode
- added Ctrl+F for the outline panel (#326)
- on opening the shortcut dialog, the filterTextBox has now focus
- added MemberItem#ToString()
Merge pull request #380 from Gama11/ShortcutImprovements

Some shortcut improvements
Merge pull request #352 from Gama11/RefactorMoveFile

Refactor->Rename: don't reload renamed files
Merge pull request #348 from Gama11/DuplicateFileError

Add Confirmation popups for duplicate files errors
Merge pull request #369 from Gama11/AddClosingBraceRefactor

Rewrote "Add closing braces", closes #357