Log Message:
Update tmux to 1.8.

Incompatible Changes
====================

* layout redo/undo has been removed.

Normal Changes
==============

* Add halfpage up/down bindings to copy mode.
* Session choosing fixed to work with unattached sessions.
* New window options window-status-last-{attr,bg,fg} to denote the last
  window which was active.
* Scrolling in copy-mode now scrolls the region without moving the mouse
  cursor.
* run-shell learnt '-t' to specify the pane to use when displaying output.
* Support for middle-click pasting.
* choose-tree learns '-u' to start uncollapsed.
* select-window learnt '-T; to toggle to the last window if it's already
  current.
* New session option 'assume-paste-time' for pasting text versus key-binding
  actions.
* choose-* commands now work outside of an attached client.
* Aliases are now shown for list-commands command.
* Status learns about formats.
* Free-form options can be set with set-option if prepended with an '@'
  sign.
* capture-pane learnt '-p' to send to stdout, and '-e' for capturing escape
  sequences, and '-a' to capture the alternate screen, and '-P' to dump
  pending output.
* Many new formats added (client_session, client_last_session, etc.)
* Control mode, which is a way for a client to send tmux commands.
  Currently more useful to users of iterm2.
* resize-pane learnt '-x' and '-y' for absolute pane sizing.
* Config file loading now reports errors from all files which are loaded via
  the 'source-file' command.
* 'copy-pipe' mode command to copy selection and pipe the selection to a
  command.
* Changes panes can now emit focus notifications for certain applications
  which use those.
* run-shell and if-shell now accept format placeholders.
* resize-pane learnt '-Z' for zooming a pane temporarily.
* new-session learnt '-A' to make it behave like attach-session.
* set-option learnt '-o' to prevent setting an option which is already set.
* capture-pane and show-options learns '-q' to silence errors.
* New command 'wait-for' which blocks a client until woken up again.
* Resizing panes will now reflow the text inside them.
* Lots and lots of bug fixes, fixing memory-leaks, etc.
* Various manpage improvements.