Inline Message Viewer

Show lint messages inline, next to the code that it applies to.  See
the new gif in the readme for an example.
Almost 'unfixed' a bug...
Typo
Clean up

I’ve also brought in the message class from being a node import to
being directly in inline-view.coffee.  This allows greater control of
the message and the node package was created by me anyway.
Switched to spacepen markup
Example Gif
Merge branch 'inline-message-view' of github.com:mdgriffith/Linter into mdgriffith-inline-message-view

Conflicts:
	lib/linter-view.coffee
	stylesheets/linter.less
:lipstick:
Don't enable inline view by default yet

Let's ship it disabled for a bit to test it out first.

Test Plan:
Crossed fingers
Split linter.less into one file per view

Test Plan:
Turned on all views and made sure styles seemed ok for a file with one message.
Use correct variables
Remove unneeded import
:lipstick:
Variable width inline view, sized to content

Test Plan:

Looked at a lint message. Edited the message in the inspector to make it really
long, to see what happened for linebreaking. It wraps eventually so this seems
good enough.
remove unused import
Destroy linterviews before other views
Stop Atom from crashing upon exit

In `deactivate`, `remove` is called, but before this change, `remove` doesn't
exist. The real fix for this is probably to make `InlineView` a real `View`,
but for now this will stop errors.

The fact that Atom crashes is a separate issue that I'll make a report for.

Test Plan:
Press `ctrl-cmd-opt l` and Atom doesn't crash
Merge branch 'mdgriffith-inline-message-view'