Update MCA to include polymer fixes.
Pull in start-up fixes for dart apps.
Add elementtree to mca for XML parsing
Minor syntax issues; function hoisting
Add scan-manifest internal command for pre-prepare hook
Add pushMessaging, power, idle to mca.js plugin mappings
Cleaned node_modules to save 35M
Adding procedure to clean node_modules
Create CONTRIBUTING.md
Update platform submodules & CLI snapshot to 3.3.0. Update cordova-plugin-file to current dev branch

cordova-android is actually a couple commits past 3.3.0 to include the defaults.xml commit.
Revert "Add scan-manifest internal command for pre-prepare hook"

This reverts commit c01132095c6d8e6171e355bdaa62e3bde390a972.
It was blanking out the appID, and was not preserving config.xml
formatting
Updating chrome-cordova submodule
Merge branch 'dev'

Main change is using history.replaceState() instead of custom CORS proxy.