Make the CIDict interface match standard dict (except view* methods).
Add __contains__, __iter__, clear.
Add keyword and iterable support for __init__, update.
Also add values() and itervalues(). Previously the dict versions were
used; the new ones guarantee that the order matches keys().
Mark view* methods as not implemented.
CIDict.copy() now returns a CIDict.
Test the above additions, and fromkeys() which worked but wasn't tested.
Petr Viktorin
0226064bac