Log Message:
Update to 0.12

Upstream changes:
0.12, 2014-02-08

Fixed RT#81077: useall fails in taint mode
Thanks to Aran Deltac, who contributed the implementation and test.

Fixed RT#83596: Documentation doesn't describe behaviour if a module fails to load
Clarified documentation for useall and usesub.

Fixed RT#62923: setmoduledirs(undef) doesn't reset to searching @INC
Added more explicit tests.
Thanks to Colin Robertson for his input.