edit-server-new-frame: clean-up and re-factor (ref pull #97)

A pull request to fix up focusing of the new frame on MacOS lead me to
re-factor this code so all the frame raising logic is common for the
new-frame and re-use frame options. Also:

* Clean up tabs
* Clean up doc string
edit-server.el: change order as suggested by @ranmocy
edit-server.el: add edit-server-edit-mode-hook (#91, #94)

This provides a late hook for once every thing is set-up and the user
may want to mess with the display. You shouldn't use this hook for
setting modes as this will likely confuse the minor mode magic we are
using.