source.el: Remove srcbuf-describe in source which was duplicated in helper.
Remove a compiler warning for buffer-killed?
core.el: Add debugger name in error a comint shell error message
rest: Use colon (:) for package delimiter on some "describe" functions.
More ignore
Make sure we keep separate two invocations that cannonicalize to the same command buffer.
For example "bashdb /etc/profile" and "bashdb /tmp/profile" will canonicalize to buffer
"*bashdb profile shell*", but these must remain distinct. We uniquify the former buffer.