Android build

 - fix cross-compile issues
 - workaround android bug with c++11 and string viz. https://code.google.com/p/android/issues/detail?id=53460
 - disable warnings not fixed in android build yet

This file reimplements C++11 string methods that we use in our code. That's why they are in std namespace.
For more info see
http://stackoverflow.com/questions/17950814/how-to-use-stdstoul-and-stdstoull-in-android/18124627#18124627
https://code.google.com/p/android/issues/detail?id=53460