initial commit

just an initial step. it allows explicitly close the session from the
Live Development icon and it also closes the session after the last
connection was closed.
Merge branch 'session-close-u' into session-close-d
add session support for page reloading

add STATUS_RELOADING to support use cases the need to reload the page
(eg. editing JS files) without closing/open the entire session.
Merge branch 'connections-d' into session-close-d
Merge pull request #24 from sebaslv/session-close-d

Session close (initial step)