Now Ctrl-s to save file (requires stty -ixon) because Z is too close to ZZ!
stty +ixon to allow Ctrl-s and Ctrl-q to be used during vim session
optionally allow flashing the cursorcolumn too (disabled by default)
dodgy implementation of background flashing, soon to be improved!
enable and disable ability to use ctrl-s and ctrl-q in vim, using stty -ixon.  May need a bit more work to be friendly for all users
dim_inactive_windows intial version
dim_inactive_windows version I like
windows_remember_size performing dim-inactive-window behaviour by not clearing his flash
windows_remember_size back to normal behaviour
windows_remember_size has flash disabled by default
for now, only run in gui mode; define own highlight name