Blender Git Loki

Depsgraph: Add extra name tag for operation nodes

The idea here is to address issue that name on it's own is not
always unique: for example, when adding driver operations the
name used for nodes is the RNA path (and multiple drivers can
write to different array indices of the path). Basically, now
it's possible to pass extra integer value to distinguish
operations in such cases.

So now we've already switched from sprintf() to construct unique
operation name to pass RNA path and array index.

There should be no functional changes yet, but this work is
required for further work about replacing string with const
char*.