Fixed the files to actually build successfully.

There were a lot of bugs here. Please make sure that methods have the
correct number of arguments and such.

Also, these files have a lot of tabs. No tabs pls.
Debugged parser, linked to external process test.

Nothing super interesting in the debugging.

KNOWN BUG: the parser will fail if there is a space between < or >
and the beginning of the file path.
Hooked up the shell to the helper function.

External and internal commands are now working. Piping and file
redirects were originally not believed to be working, but further
investigation has revealed this to be an emergent problem. They are
indeed working.
Fixed redirect parsing bug.

< and > can now properly be followed by any number of spaces before the
file name. Some code to check for parse failures was also added, but
this is not currently working.