Toggle for what's new active indicator

#73
First pass at hiding what's new for first time user

Paired w/ @nevraeka
Hide what's new star on initial toolbar draw

Paired with @terrasea

#73
Convert what's new menu to a proper menu item

For consistency and, through that consistency, the default behavior of closing upon
click.

Paired with @terrasea

#73
Remove what's new star when what's new is clicked

#73
First pass at settings

#73
Persist settings in localstorage and save whats_new click therein

Paired with @terrasea

#73
Bump to new version for a beta check
Switch to dart:js for all js-interop

Paired with @terrasea, @alexgchacon

[Fixes #77]
Dot git ignore build directory
Ignore query/queryAll hints, but include all others

Had been ignoring js-interop hints, but no longer need to with the switch to
dart:js.

Paired with @terrasea

[Fixes #68]
Hitting the enter key does not add newline to top of code

#78
First time users behave as if they already clicked what's new

Store that value in settings so that they never see the what's new indicator
on the menu button or see the what's new menu item highlighted.

Paired with @simonegiacomelli

Fixes #79