standalone executables.

can handle environment variables cleanly.

A test case test_sbml_support.py which inturn calls to write moosewriteSBML which needs networkx which is added as a dependency for travis

update-repository is moved from scripts to moose folder which pull the code from submodule recursive

Added build script to build all code in one go, modified update-repository to alleviate detached head issue in submodules

Changed bootstrap to a logically correct and sensible name, modified it to checkout moogli correctly