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.
Support for boost-1.51.0
Re-add support for using a 32bit NDK on 64bit hosts
Remove defines from user.hpp that are already in user-config.jam

All 3 defines are defined in the specific user-config. Removing them
allows one to add support for non-arm architectures on Android.
Remove obsolete android.py and android.jam

The files aren't necessary since gcc.jam is used for compliation.
Merge branch 'dev-boost-1.51.0'

# By Michael Zoech
# Via Michael Zoech
* dev-boost-1.51.0:
  Remove obsolete android.py and android.jam
  Remove defines from user.hpp that are already in user-config.jam
  Support for boost-1.51.0