Some fixes/safeguards to our simulation plugin.
A stupidily HUGE commit regarding our CellML-related code. Note that, at this stage, the CellML annotation plugin doesn't work anymore. We need to do some more work on our new RDF code.

OpenCOR doesn't use its own internal representation of a CellML file
anymore. It was just going to be too cumbersome in the long run. The
only thing we are keeping is the RDF stuff since we did add quite a bit
of a layer on top of what the CellML API offers. In the process, we
also improved our use of ObjRef.
Some work on our CellML-related code.
Better handling of a snapshot information which is now retrieved within our CMake script and also used as part of our packaging.
Fixed a silly mistake.
Disabled the Raw and Raw CellML views in preparation of version 0.1.

This means that we also disabled our QScintillaSupport and Viewer
plugins since they are not used by other plugins.
Disabled the Raw and Raw CellML views in preparation of version 0.1.
Fixed a crash that occurred when trying to run OpenCOR after having manually deleted a plugin.
Forgot to remove a trace.
Fixed a small issue with showing/hiding menus.
Some minor cleaning up.
Wrong casting which worked on Linux, but not on Windows and OS X.
Revert "Some minor cleaning up."

This reverts commit fbcbd5148ff8da11041f7f93db45846dfe92976e.
Some minor cleaning up.
Done on reworking our CellML-related code.
New snapshots.
Minor cleaning up of our main CMake file.
Minor cleaning up of our main CMake file.
Better handling of variables defined in imported components (#112).
Added support for Google Analytics to our main and download web pages.