Avoid flush if blending doesn't need to be changed.
Improved native library extraction and loading.

I've found a small percentage of users can't write to the temp directory. Eg:
https://code.google.com/p/libgdx/issues/detail?id=1504
These changes improve the chances of being able to extract and load a library. For load(), multiple locations are tried to extract and load the library. For extractFile(), multiple locations are tried to extract the file.
Merge branch 'origin/master'