Added tarball of zxing v2.1, as tarball from code.ros.org is no longer compiling under ubuntu 14.04. Fixes error in build/core/src/zxing/aztec/decoder/Decoder.cpp:45:35: narrowing conversion from 'int' to 'char'
Adapted precompled header paths to be expressed relative to the metapackage and not above. Adapted Makefile to include new cpp files. Reduced include headers