Some work on allowing a file to be locked/unlocked (#256).
Some minor cleaning up [ci skip].
Some work on allowing a file to be locked/unlocked (#256).

Now works on all our supported platforms (i.e. Windows, Linux and OS X).
Some minor cleaning up [ci skip].
Some work on allowing a file to be locked/unlocked (#256).
Some work on allowing a file to be locked/unlocked (#256).
Some work on allowing a file to be locked/unlocked (#256).
Some work on allowing a file to be locked/unlocked (#256).
Bypass shortcuts used by QsciScintilla.
Some minor improvements on our file manager class.
Some minor cleaning up.
Make editor-based views reddish for locked files.
Fixed a couple of issues with locked files and editors.
Enable/disable the Locked menu item depending on whether the current file is modified.
Enable/disable the Duplicate menu item depending on whether the current file is modified.
Minor improvement to the un/locking of a file.
Some more work on our CoreEditing plugin.
Slight update to our .gitignore file [ci skip].
Some minor cleaning up of our common CMake file.
Slight improvement to our CMake code for retrieving a binary file.