oe.terminal: add tmux classes

This adds two new Terminal classes. It's separated into two, so that opening
a split inside a tmux window is preferred to the other terminal types, but
opening a tmux session is prioritized only slightly higher than screen.

- tmuxrunning: Open a new pane in the current running tmux window. Requires
  that the TMUX variable be added to the env whitelist to use it.
- tmux: Open a new tmux session

(From OE-Core rev: 10f64d202ceb230c3c79e09dce182ffce94d1117)

Signed-off-by: Christopher Larson <chris_larson@mentor.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oe/terminal.py

@@ -107,6 +107,7 @@ class Screen(Terminal):
 
 class TmuxRunning(Terminal):
     """Open a new pane in the current running tmux window"""
+    name = 'tmux-running'
     command = 'tmux split-window {command}'
     priority = 2.75
 
@@ -119,7 +120,7 @@ class TmuxRunning(Terminal):
 
         Terminal.__init__(self, sh_cmd, title, env, d)
 
-class TmuxNewSession(Terminal):
+class Tmux(Terminal):
     """Start a new tmux session and window"""
     command = 'tmux new -d -s devshell -n devshell {command}'
     priority = 0.75