Log Message:
Updated cairomm to 1.12.2.

1.12.2 (stable):

* Remove new API that was not meant to be added in 1.12.1.

1.12.1 (stable):

* C++11: Use nullptr instead of 0.
* C++11: Use override keyword on destructors.
* C++11: Make operator bool() explicit.
  (Murray Cumming)