Calculate condition-info correctly

The exception message information was blank for breakpoint and step events.
Correct the regex for implementation fields

The regex for matching implementation fields in stack frames was wrong.
Enable line breakpoints

Enables setting of line breakpoints with nrepl-ritz-line-breakpoint, bound
to C-c C-x C-b.  Requires nrepl-ritz-break-on-exception to be on.
Make nrepl-ritz-jack-in use nrepl-jack-in
Add a load-file middleware

The load-file operation adds optional disabling of local var clearing,
and dead var removal.
Recreate breakpoints on load-file

Breakpoints were not being recreated when code was recompiled for load-file.

To do this, it adds a message reply hook, for notifying a function on the reply
to a specific message.