Partially revert "Updates to latexmk, texparser."

This (partially) reverts commit a492bd9aceb0bf3b1107e99ab6fcf9648ef9a0b6 and fixes #26.

Presumably during debug someone commented the exit code propagation which broke the automatic closing of the HTML window.

I reverted all changes to the tmCommand, since the original commit was only about updating latexmk.pl (and some tex parser update, which should probably have been factored out into its own commit with corresponding log).

The info.plist had metadata added that should only appear in managed bundles, but this was already reverted (sans the doc type) in ab2f3010.
Typeset & View would report an error for some users

Fixes #62
Fix label completion (⌥⎋)

It now works with empty braces, does proper snippet escaping of inserted text, places caret correctly, etc.