Some minor cleaning up.
Slight improvement to our find/replace widget in EditorWidget (#261).
Fixed the issue with local and remote files not being properly distinguished on Windows (closes #328).
Can now close a file using Ctrl+W on Windows (as well as with Ctrl+F4; closes #330).
Fixed the issue with not being able to open a recent local file on Windows (closes #331).

I had forgotten something while working on issue #328.
Fixed the issue with folders and files not getting remembered from one session to another anymore in our File Organiser window (closes #329).

This was caused by commit f4682b158504b2c61eca1acfc68a09f2d2505465,
which was the result of some Xcode analysis (!?).
Slight update to our user documentation (#329) [ci skip].
Some minor cleaning up [ci skip].
Some minor cleaning up.
Minor fix to our file manager [ci skip].
Some minor improvements to the way our file manager checks files.
Some minor cleaning up [ci skip].
Improved our file manager by handling the case of file not being readable anymore.
Reorganised the user documentation for our plugins [ci skip].
Updated the screenshots for our Help plugin documentation [ci skip].
Only use Google Analytics for the website itself (i.e. not locally or within OpenCOR) [ci skip].
Some minor updates to our user documentation [ci skip].
Some minor cleaning up.
Updated the user documentation related to the RawView plugin (closes #77) [ci skip].
The qjpeg plugin from Qt is necessary if we want to be able to render JPEG images (as is required for our Help plugin).

Incidentally, everything is actually OK without this plugin on Windows
and Linux. It’s just on OS X that it is really needed. Still, it can’t
harm having it on Windows and Linux too.