- Cherry picked #10662 and fixed merge conflicts.
- Manualy merged the change from #11904.
- Did not merge #12236 since I'm not sure whether the issue
affects Godot 2.1 and I don't have VS2013 to test.
- Did not merge #11843 since it doesn't seem relevant (the
code is only needed for creating DONORS.md, etc.).
- Did not merge #10727 and #11752 since they seem to be
already included in #11742.
- The Windows and Linux builds have been tested with Scons 3.0
using Python 3.
- OSX and iOS should hopefully work but are not tested since
I don't have a Mac.
- Builds using SCons 2.5 and Python 2 should not be impacted.
The other subfolders of tools/ had already been moved to either
editor/, misc/ or thirdparty/, so the hiding the editor code that
deep was no longer meaningful.
(Manual redo of 49c065d29c)