Install global lazy _()

The patch installs the lazy _() function, which returns translatable
Message objects, globally via the enable_lazy() method such that
translation works in all modules.

Since Messages objects can't be str()'d and native exceptions str()
their messages the patch also removes passing Messages to native
exceptions.

Change-Id: I8a4ecd904e393c4bd0308cdeafa3cf1d8f0e70fe
Closes-Bug: #1275901
Merge "Install global lazy _()"