SciTools/iris — pull request #1306 by pp-mo (2014-09-09 13:58:57+00:00)
Title: Pp stash constrain

Bugfix for problem introduced by pp constraint 'conversion' code in v1.7.
Various users had code with the idiom ```constraint = AttributeConstraint(STASH=STASH(x,y,z))```.
When used to load, 'pp._convert_constraints' refused to handle these, as it expected the test value to be a string (only). Fixed that by supporting a STASH object in the convert code.