[MlMt] prevent ESC exit fullscreen

[Andrey Ustyuzhanin]

Hello,

as I run Mailmate in fullscreen and search for something (Alt-Cmd-F) and 
then I want to clear the search results (return to normal mailbox) I 
usually do it via keyboard pressing ESC. It works in most of the cases, 
but sometimes it exits fullscreen instead (which is default OSX 
behaviour). It is annoying.

Is it possible to prevent ESC from being sent to OSX or assign ‘clear 
search’ to special MailMate command that could be triggered by 
different keystroke?

--
Kindest Regards,
Andrey Ustyuzhanin