Bumping them for every release just adds too much git
noise and history blowup.

This is probably the first and only commit where
I deliberately *add* trailing whitespace (to show
off the feature here).

Since v2 is the canonical CodeMirror at this point

So that I can put other doc-related stuff there without polluting the
root dir.

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

This normalizes the classes used by most of the modes
(reStructuredText and diff didn't fit in), and makes them all
reference a central style sheet (under theme/). It also adds a theme
option that can be set to change the theme, and defines a few
different themes (some based on old mode colors).

(now that column() does proper tab-counting, it should no
longer be used to check for start-of-line, since that's a
huge waste of time)