Adds local version of docutils for hacking. Refs #33.
Adds test case for code blocks. Refs #33.
Adds line numbering to error output. Refs #33.
Adds code alias for code-block. Refs #33.
Adds line numbering test. Refs #33.
Forces default language to none. Refs #36.
Parses code block parameter fields. Refs #33.
Implements rendering of number lines. Refs #33.
Checks for code blocks with nil field lists. Refs #33.
Updates generated C sources from Nimrod code. Refs #33.

Compiler 0.9.5 was used, since 0.9.4 has signed problems with parsing of
negative integers. The git hash for the compiler is
935bade994acdbf6a2e50669a5c21177afc5dc70.
Patches environ macosx bundle crash. Refs #33.

See https://github.com/Araq/Nimrod/issues/965 for reference.
Documents task in changes log. Refs #33.
Merge branch 'feature/t33_support_code_directive'