Fixed error reporting when build fails.
Modified to handle 64-bit versions of NDK r8e
Fixes undefined references when using Boost.Filesystem.

Currently only in 1.49 version of boost.
Removed patch to bootstrap.log from boost-1_48_0.patch.
Merge branch 'master' of https://github.com/readium/Boost-for-Android
HOST_* variables are now logged.

The are: HOST_ARCH, HOST_OS, HOST_EXE, HOST_TAG and HOST_NUM_CPUS.
Had to pospone finding of there variables after the name of the
log file was determined.
Corrected the Platform variable for cygwin and windows.

Should be just 'windows' not 'windows-$HOST_ARCH'
Adds more tests and debug output to the script.
Re-add support for using a 32bit NDK on 64bit hosts