Improve CMS Exception handler.
Previously Twig syntax errors inside a component partial would show the incorrect file and line number. This is fixed.
Also simplified the approach so the stack trace is not hidden inside a closure.
Components now support a shared /components/partials directory used as a fallback when a partial is not found.
Commented out the refresh button, the usage is not 100% clear and can cause destructive damage.
Fixes minor bug
Make {{ this.controller }} available
Cause a scene when Twig extensions fail, instead of failing silently
Add Theme::exists(), Fix getPath()
Merge pull request #351 from Flynsarmy/themeFixes

Add Theme::exists(), Fix getPath()
Tidy up code
Fix docblock
Update RU lang (build 110)
Minor improvements in the pagination and lists
Display a correct CMS object name in the page title. Fixes #28. Fixes #354.
Fixed the unknown component caching problem. Added the unknown component handling to the back-end. AJAX request can now be stopped with preventing default action in the oc.beforeRequest event. Fixes #46.
Fixed a problem with pinning the sidebar in the CMS area on MacOS.
Fixed a bug where clicking a tab in the CMS area doesn't activate the tab pane. Closes #126.
Create a System Twig extension, for shared features
Refs #350 - add default sender address
Minor text updates
Fixes #55 - Assets are now referenced correctly as Assets instead of URLs