Fix #35252: Crash with the node placed partially behind the screen

Issue was caused by negative maximal possible text width happening
in label clipping.

Solved by clamping width to 0 if it's negative.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@56572 954f8c5b-7b00-dc11-b283-0030488c597c
Fix #35093: New Basis shape key doesn't act as Basis

Made it so Move Shape Key ensures first key is a refkey,
so now it's possible to change basis key from the interface.

It's still needed to manually teak key's relative_key,
not sure whether there's a reliable automated way to tweak
this value when bassi key is changing.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@56573 954f8c5b-7b00-dc11-b283-0030488c597c
fix for recent commit, WITH_GUARDEDALLOC wasn't enabled for makesrna, makesdna.


git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@56574 954f8c5b-7b00-dc11-b283-0030488c597c