Work on #218: make sure to initialize history to prevent null pointer.
Fix #227.  Skip escaped delimiters when finding balanced text objects.
Update unstable update site.
Add a couple more unit tests.
Fix build warnings.
Add stubbed command line to test code to keep tests working.
Test other exit medhods.
Improvements for #218: fix backspace cursor, fix delete previous word.

Upon backspacing the last character, the caret was moved before  the text
content was changed. The caret was thus rendered as a line when it
should be a rectangle.

Delete previous word deleted a whole word plus the letter of the next
word, reverted code to state before command line changes.
VIM-like C-W handling in the new command line mode.

After removal of ':' character from the command line content
delete word back needed a bit of tweaking.
Improvements on #218: setPosition after deleting a word, update caret.
Update unstable update site.
Implemented `:only` for splits `C-W C-O` and `C-W C-W`.

Added the following command and key mappings:

- `:wincmd[!] o' to remove all splits by either moving all editors into
  the current split or (with `!`) closing other editors. Mapped to `C-W o`
  and `C-W C-O`.
- `:wincmd w` to switch to most recently active split. The behaviour is
  different to VIM: in VIM `C-W C-W` cycles through all the splits
  moving down/right. To implement that would require editor coordinates
  which is not trivial to obtain.
Merge pull request #230 from igrekster/win-only-switch

Implemented `:only` for splits `C-W C-O` and `C-W C-W`.
Fix #228: Move LinkedModeHandler code, check for disabled mode.

Moved LinkedModeHandler to the net.sourceforge.eclipse.interceptor
package, made it so that LinkedModeHandler is created in
VimInputInterceptorFactory instead of the UserInterfaceService.

LinkedModeHandler now checks if the VrapperPlugin is enabled before
switching modes.
Cleanup after #228: remove unused ModeChangeHintReceiver.