Call hide on the views instead of the jQuery collection

This ensures that views with custom ::hide methods can invoke special
behavior.
Don't measure lineHeight/defaultCharWidth when editor is hidden
Avoid measuring lineHeight/defaultCharWidth on show unless needed

We only need to re-measure if the fontSize, fontFamily, or lineHeight
changed while the editor was hidden.
Rename lineHeight to lineHeightInPixels to distinguish from CSS value

CSS has a line-height property with values like '1.3', but we also have
a measured pixel value for line height. It's important to keep these
separate conceptually.
Re-measure the line height in pixels when the CSS line-height changes
Add specs for updating lineHeightInPixels when changing font size/family
Wire editor.lineHeight config value
Upgrade space-pen so $.fn.views doesn't return undefined values
Merge branch 'master' into ns-ks-react-dont-measure-when-hidden

Conflicts:
	spec/editor-component-spec.coffee
	src/editor-component.coffee
	src/editor-scroll-view-component.coffee
	src/lines-component.coffee
Merge pull request #2344 from atom/ns-ks-react-dont-measure-when-hidden

React: Don't measure line height / char width when editor is hidden