update submodules on checkout
Merge pull request #71 from vcstools/submodule_updates

update submodules on checkout

Tests ticketed in #75
fix #75: makes sure cloning a branch with submodules only fetches the submodules of that branch (not the default)
Merge pull request #76 from tkruse/submodule_updates

fix #75
0.1.31
no more shadow