patch to give user the option of detaching tmux windows upon closing
small bugfix, also inform users that there is an option to detach in the alert window
made the alert text shorter
changes to dialog text as per gnachman
changed detach button label
in response to code review comments by gnachman
Merge pull request #187 from subhasis256/master

Add option of detaching tmux windows upon closing to alert shown when closing window with tmux tabs