Rewrote function for syncing with individual MESS users and accounts

I rewrote the functionality for syncing with individual mess users
and accounts when a member and/or account is brought up at the
register.

The old way: ruby scripts that were executed syncronously. These
scripts could cause IS4C to hang when MESS was unresponsive.

The new way: an ajax callback that operates asynchronously and
updates the display with the member's balance, equity owed, etc.
when the callback returns.

I also updated BasicPage.php with a red/green dot to test if MESS
is online, which should help cashiers understand if the members
and accounts are properly being synced when the account is brought up.
Additional edit to BasicPage.php to support new MESS Online status