Change packaging from Stitch to Browserify

Please note that I have temporarily pointed the package.json values for `rendr` and `rendr-handlebars` to my updated repos. Obviously, we'll need to change this to new tag numbers once the browserify update is in a tag for each repo.

This PR implements browserify for examples 00, 01, 02 and 03. Example 04 has other errors (such as not being updated for the moved app_view file) which need to be corrected before browserify makes sense.

I have also submitted a related RP for `rendr-handlebars`.

Related RP: https://github.com/airbnb/rendr-handlebars/pull/8