Fix typo in autocompletion list
Change sample param end: to finish: 

* Avoids confusion with the ruby end keyword
* Fixes bug with new cold folding functionality
remove old cruft
don't require start-server script to be executable:

* uses ruby command directly and passes script as a parameter
* Need to consider how this might work on Windows machines if Qt GUI
  is ported there.
Add code folding functionality and nesting indicators:

* Also extract out workspace init code into a separate function to
  reduce duplication.
Add missing ) paren
add missing function definition to main window header
further interface tweaks