[solarized theme] Remove tab background character

It doesn't belong in a theme.
[vim] Fix bug that vim mode could not be disabled
[vim] simplify selectBlock function
Link to new discussion forum
[vim] improve handling of external selections
[real-world uses] Add three links
Allow calling the constructor with null as place

Issue #2893
[vim mode] Don't directly access .options
[vim] implement gu and gU
Support attach and detach methods for key maps

And adjust vim mode to use these.
Allow non-normalized keys and multi-stroke keys in keymaps

As long as CodeMirror.normalizeKeyMap is called on them before they are
used. This interface is a little weird, but backwards-compatible.
Update the manual to reflect new keymap situation
[meta addon] Added Django and RPM modes
Don't blindly refresh on resize event, compare new size instead
[closebrackets demo] Make mode match editor content
[closebrackets addon] Count quotes as okay to autoclose in front of
Work around Webkit wrapping issue

Issue #2901
Workaround for an error in getting to insert mode.  It was very difficult to reproduce, and I don't know
what led to it, but the ">" mark was set but returned undefined when find() was called.  This should work
around the problem if it happens again.
[vim] Make vim fail more gracefully
[3024-day theme] Change color of matching bracket

The color white is not visible on the current backgroung