Remove altercation's solarized repo.

There is an issue displaying gray in the dark color scheme (issue #220). Gray
and the background color are the same, making it impossible to see. Tools like
jshint-stylish, gulp, grunt, and yeoman all display text in this color, which
is unreadable.
Replaced solarized with hydrozen's fork.

There is an unfixed issue (#220) with the original Solarized scheme that
renders gray the same color as the background, causing much of the output for
things like yeoman and jshint-stylish to be invisible.
Set up bindings to open new panes in cwd.

Default behavior for splitting vertically and horizontall is now to open in
the same directory. Capital letter versions of those keybindings open in ~.
The reverse is true for new windows: default new window behavior is opening in
~, a capital A opens the window in the current working directory.
Color scheme back to Solarized Dark.

I didn't remember changing this. Put it back.