Bug 1109157 - fix mozrunner problems in marionette-js-runner, recommit p...

...ackages

For this, I removed node_modules, installed using 'npm install --ignore-scripts' and updated .gitignore to ignore the python egg and virtual environment, since --ignore-scripts doesn't seem to be called on imported packages.

We need to update this since we were missing packages in marionette-js-runner, causing failures like https://ftp.mozilla.org/pub/mozilla.org/b2g/try-builds/gaiabld-e39fc7640257/gaia-try-linux64_gecko/gaia-try_ubuntu64_vm-b2gdt_test-gaia-js-integration-1-bm116-tests1-linux64-build668.txt.gz