[tmux] Rename tmuxcolors-dark.conf -> colors-dark.conf
[tmux] Rename tmuxcolors-light.conf -> colors-light.conf
[tmux] Move color themes into their own directory
[tmux] Resize panes by dragging their borders with the mouse
[tmux] Remove key bindings to maximize and restore a pane
[tmux] Use default key binding to kill current pane
[tmux] Remove key binding to log output to text file
[tmux] Set escape-time to 0 milliseconds

The escape-time is the amount in milliseconds for which tmux waits after
the Escape key has been pressed to decide whether it's part of a key
sequence or not. The default is 500 milliseconds.

Might as well set it to 0 milliseconds since there is no difference
between having 1 or 0 milliseconds in this case. In other words, I don't
normally use Emacs, but when I do, I hit Escape until I'm back in Vim.
[tmux] Add key binding to open new window with current path
[tmux] Add key binding to split panes with current path