Blender Git Loki

Fix for nasty Heisenbug(tm): C++ enums can only be used as flag values
when the variable is of type int.

With short etc. any concatenation ("|" operator) of flags will generate
an int, and in this case was overwriting neighboring fields in
OperationDepsNode ("flag" and "done" fields), which was causing havoc
in the scheduler.

Alternatively a specialized flag type can be defined. See here for
further info on the issue:
http://stackoverflow.com/questions/1448396/how-to-use-enums-as-flags-in-c