v2.5.3

This is the last release that supports gnu binutils, as in new versions of NDK the support of it is just dropped.
It is still possible to use -binutils argument to choose between llvm and gnu binutils. The upcoming release will support only llvm.

Aslo, the libvpx was updated to 1.11.0 and its compilation for armeab-v7a when llvm is used was fixed.