Functionize error dumping, in case another module needs it later.
Lambdas show trace properly now. Finally fixes #41.

A few things had to happen for this:
* String loading now takes a name that will be used for the filename.
* Lambda error line number is patched down into the original file that gets
  printed when there is trace.
* The main runner now removes printing for entries that start with [lambda]
  since lambda information is just for parser, and makes no sense in output.

With this commit, I declare lambdas to be working properly. I fully admit that
they're not as useful without being able to become closures. However, I
believe that should be done in a different set of commits (#51 addresses
functions being closures, and that includes lambdas too).