ratasm 0.1.1

Fixed

• The program-counter marker is tied to the file execution stopped in. It was
  drawn wherever the stopped line number matched, so in a project with more
  than one source it marked an unrelated line in whatever buffer was showing.
• Document lookup compares whole trailing path components rather than the bare
  file name, so src/main.asm and lib/main.asm are no longer the same file.
• Stepping into a source that is not open opens it, instead of leaving the
  editor on the previous file as though execution had never left it.
• Jumping to a build error goes to the file the diagnostic names. The cursor
  moved in whatever document was active, which in a multi-source project is
  almost never the right one, and a failed build does this automatically.