This fixes the case where the effect vanishes, but we still hold an invalid pointer to a parameter of that effect. With the new code, the effect will not vanish as long as an effect pointer exists.
However, all effects must be created either through std::shared_ptr or std::make_shared. If they were not made through one of those means, the code will crash on the ->shared_from_this() call.
To further distance the code from having to do too much manually, the graphics context is now available as a managed class. All places that previously used obs_enter_graphics and obs_leave_graphics are now using the new gs::context class instead.
The number of files in the source directory was a little bit much and just made file naming more complex than it had to be. Therefore all files were moved into subdirectories where it matters.
Filters now reside in source/filters/, Sources in source/sources/, OBS Wrappers in obs/, OBS GS Wrappers in obs/gs/, Transitions will reside in source/transitions, Graphics Helpers will be in gfx/.
