Allows a user to execute `dlv trace [regexp]` and Delve will execute the
program and output information on functions matching [regexp].

Also, reorganizes some code.

Initially, the `proc` package emitted a lot of output. Now, that should
not be the case. The `proc` package should never print, for any reason.
That should be handled by clients.

We do not need to verify a current breakpoint, nor do a redundant check
on whether we have been asked to manually halt. Assume trapWait has done
its due diligence and stop the world once it returns.

Also, kill whitespace to make code appear more as a singular block for
readability.

Major source cleanup, still not finished. Removes gross control flow.

Instead of fighting against the normal flow, just signal a SIGTRAP and
let the existing flow handle it, as long as we set the halt flag
correctly the system should halt.

Fixes #95