fix bad merge
put back makeenv core as one file with separate gmsl install
merge modules/core.mak to makeenv.mak
fix bug in var_ifdef - no longer warns on undefined 2
refactor lib install and reorder makeenv.mak
Revert "move to pbr"

This reverts commit cbd4d3488949f527ff63be2c923f6d4ee0be78c6.

Some sillyness going on with pbr that messes with deps - to be fixed
drop LIB_DIR not used
use setup.py not nasty regexes
simplify lib install
better error in mock curl
use custom test command for nose
better bootstrap makefile
better clean
better make_lib
which needs PATH
change order of relpath arguments
force symlink for when make is forced
export SHELLOPTS
improved shell support + refactor tests to be more robust
use VENV for relative path to venv and make this the target in place of VENV_PYTHON