Brings new bounds limiting and also prepares build system
for the changes in the upstream.
Namely shared_ptr header and namespace is now being detected
by a build system rather than by hacks in the code.
This commit includes some changes to auto-detection flags
in SCons, presumably adding more consistency there. This
is main changes which are suppoed to be reviewed here.
Reviewers: campbellbarton
Differential Revision: https://developer.blender.org/D581
