style(core): make code formatting more consistent for Angular.js file

This commit changes the code formatting of the Angular.js file to adhere
more closely to Google's JavaScript style guide. It also removes some
unused variables, while renaming others to provide more clarity as to
what it does (e.g. `ii` to `attributePrefixLength`).
style(core): wrap code to a max length of 100

This commit fixes several lines in the main Angular.js file that are
longer than 100 characters (which is the intended limit as noted in the
contributing docs). One line still exceeds the max length of 100 chars,
which is a link to a wikipedia article. We can't properly break up this
line as it will break the markdown formatting (and the link), unless
we shorten the URL.