Add set_layout helper to allow easy use of Tmux's select-layout command

[jimeh]

Example with layout string copied from the list-windows command:

set_layout "61de,238x73,0,0{118x73,0,0,1,119x73,119,0[119x36,119,0,2,119x36,119,37,3]}"
select_pane 0
run_cmd "htop"
select_pane 1
run_cmd "sensors"
select_pane 2

This could be useful when relying on one Tmux's five built-in layouts, or if often making small adjustments to a specific window layout. Instead of adjusting split_v and split_h commands, you can just get the layout string from tmux list-windows and paste it in.

[abelcheung]

A "me too" here as first time user, finding that select-layout support is something to be desired. It would be also nice to be able to specify how many panes to be splitted when using the 5 default layouts as well.

[jimeh]

I haven't used select-layout much, but I'm assuming what you mean is that Tmuxifier would add/remove panes till the window had the desired number of panes, and then apply your specified default layout right? :)

[abelcheung]

There are 2 cases to be considered. First one is exactly what you described: for a fixed layout, it is desirable to add/remove panes until it matches with the layout string.

Second case is for layout not fixed ahead. In tmux speak it is like:

splitw
splitw
splitw
.......[more splitw]........
select-layout main-vertical

So a hypothetical setting of set_layout main-vertical [n] can automatically create a layout with a single large pane on left side and n-1 panes on right side, without need to add any split_[vh].

[leesei]

This will help #9.