Support for NDK r9 on 64 bit platforms

Credit goes to David Faure.
Add a possibility to select a toolchain
Add a support for Boost-1.54.0
Merge pull request #47 from jauhien/boost-1.54

Add a support for Boost-1.54.0
Update README.md
Add a support for NDK-9b
Merge pull request #54 from jauhien/ndk-9b

Add a support for NDK-9b
Add support for boost-1.55.0
Merge pull request #55 from jauhien/boost-1.55

Add support for boost-1.55.0
Update README.md