Added cURL android build script.
https://github.com/openpeer/opandroid/issues/613
Fixed paths in curl-build-script
https://github.com/openpeer/opandroid/issues/622
Fixed build scripts to use proper compiler and target architecture.
https://github.com/openpeer/opandroid/issues/622
Fixed build scripts to use proper toolchain for curl.
https://github.com/openpeer/opandroid/issues/622
Fix for NDK path.