Add simple project management features

[benvanik]

anvil setup

• Install/update dependencies:
  • node_modules via NPM
  • python packages via easyinstall/pip
  • system packages (somehow?)
  • custom scripts?
• Fetch third_party by git submodule init/update
• Accept diff of items to run vs. full

anvil pull

• Stash current setup information
• git pull
• Re-run setup with diff

anvil push

• Run presubmit rules (full build/lint/test/etc)
• git push

anvil update-submodules

Replaces update-third-party.sh

for each gitsubmodule:
  cd $m
  git checkout master
  git pull origin master
  git merge origin/master
for each gitsubmodule:
  git add $m
run full build/lint/test