workspace: move new file warning to workspace
workspace: Check the file before opening it

Close #202
Tested on linuxmint-16-cinnamon-dvd-64bit.iso
document: fix crash in editortoolbar on document close
actionmanager: free memory when removing action

Close #204
Add: code_to_rest preview
Fix: Use codechat module
Add: Codechat is added to Enki setting as a plugin. UI is defined in UISetting.ui
Fix: Fix issue #19 and #20. Preview panel refreshes on setting change. UI improve.
Fix: Delete uncessary code_to_rst output
Fix: Move settings update to plugin constructor, not settings constructor, since
       methods in plugin depend on settings existing.
Fix: UISetting: unnecessary change on currentIndex
Settings.ui/__init__.py: Change radio button to checkbox
Preview.py: Update comment
enki.default.json: Clear unnecessary CodeChat entry
Add: Mock import codechat module fail and test enki setting UI
Add: Several more test cases for codechat plugin gui.
Fix: Improve import_fail to accept multiple parameters.
Del: Use reload instead of multiprocessing for more compact, clearer tests.
Docs: Rewrite and improve.
      Move comments to docstrings.
Fix: Clean up unused imports.
Docs: Clean up, move to docstring per coding convention.
Fix: Encoding must be on first or second line of file.
Fix: Variable name fix.
Now using latest codetochat package, unicode error fixed.
Broken QIcon is removed
Fix: Erroneous check keeps preview window from reappearing.
Fix: Improve documentation of changes.
     Check on CodeToRest's availability before using it.
Fix: Strip out unnecessary code, since config to GUI sync is already handled.
     Remove test of config to GUI sync.
Fix: Grammar edit the CodeChat settings UI.