Fixes the not-increasing memory leak in openExr.

[h-schoenberger]

Developers have to call staticUninitialize(); at the end of their application.

[kdt3rd]

fyi, this will be obsolete if we switch the entire tree to c++11, the initializer I put in there when compiling w/ c++11 will auto-clean this up.

barring that, I would prefer something like an atexit-type solution, either via the constructor/destructor attributes that gcc and llvm provide, or their equivalent under win32.

With a staticUninitialize type method, there needs to be reference counting and a hope that everyone calls initialize equally that is linked against the .so to avoid dangling references to attributes if one plugin uses the same .so and has a different dlopen/close lifetime than another consumer of this stuff.

[kdt3rd]

This is fixed for c++11 and beyond, which we now require by default