branchcache: rename itervalues() to iterheads()...
branchcache: rename itervalues() to iterheads()
The itervalues() exists because branchcache() had a dict interface. Since it no
longer has a dict interface, it makes sense to have better function names.
If a person does not understand how branchcache stores info, it will be hard for
them to guess what itervalues() does.
Differential Revision:
https://phab.mercurial-scm.org/D6152
