Also some general improvements to material.css and solarized.css

So that selection inside widgets isn't affected

Issue #3342

So that the contenteditable input style doesn't look silly
on desktop.

Using the CodeMirror-guttermarker and CodeMirror-guttermarker-subtle CSS
classes to give the markers their color.

Issue #2602

Closes #2415

This is the only theme that sets font size, remove this to bring in line
with other themes.

Added .CodeMirror to end of class names so that under CodeMirror v3, the
authors intended BG/FG is used rather than the parent styling seen

Fix bad rules in themes, measure width correctly.

This will make fixedGutter work properly, and make it the only model
(no more gutter that scrolls out of view).

Also reorganizes the basic css file to be easier to modify for users.

Issue #730

Issue #432

It's tiny anyway, no need to force people to include yet another file.

Signed-off-by: Jan Keromnes <janx@linux.com>

Courtesy of Joshua Maxwell