Fix T41226: Wrong Undo on curves and hooks
Partial fix of T40824,

Fill selection for file browser moves to ctrl-shift click due to
collision with emulate middle mouse button option
Fix T41258: Crash when entering edit mode while viewport render is enabled

The issue was caused by the render engine loading edit mesh, which re-allocates
mesh array which might be referenced by other object's derived meshed.

Worst thing about this is that updating render engine happens from the end of
scene update function, after all the objects are updated and so. This is needed
so render engine gets the update objects which is correct.

The only proper way to solve the issue is to make it so viewport engine does not
leave objects in inconsistent state, meaning nobody will reference to freed data.

In order to reach this we do edit mesh loading before running objects update so
all the objects which uses that mesh will have proper references in the derived
mesh.

This also solves old creepyness which happened before when having single object
in edit mode. tweaking it will calculate derived mesh as a part of scene update,
then this derived mesh will be freed by edit mesh loading and viewport will be
creating derived mesh again.

Now render engine is expected to do nothing with meshes which are in edit mode,
but they still need to load edit data for non0meshes. It's not really easy to
do from the BKE level because needed functions are implemented in the editor.

Thanks Campbell for the review!

Differential Revision: https://developer.blender.org/D697
Use dynamically linked SDL 1.2.15 on windows x64
Fix T40958 align rotation + project individual elements not working

This is another example of transform code crappiness. Projection
snapping for objects is handled separately than regular snapping.
Luckilly for us, we have the normal ready from the raycast result and a
copy of code from ElementRotation function can do the necessary
rotations for us.

I have not enforced constraints here (arguably, maybe I should, and the
already present projection snapping should do that too but seems it is
commented out and the unorthodox order of operations here has me a bit
scared. Leaving as TODO)
Fix build player...