Keep colour theme on REPL reload

Now, the colour theme is no longer thrown out when using :r or :l.
Partially defined names should not reduce at compile-time

This has been the spec for a long time, but wasn't implemented fully since
the totality checker wasn't strong enough to find some obviously total
things. This is now switched on --- functions are checked for totality
after every mutual block, or every individual function (if not mutual).
SimpleParser: improving performance so it is usefull for real world stuff
Unification fix to avoid giving up on recoverable errors

If function names don't unify, we shouldn't try to univy arguments!
Otherwise, we can get unrecoverable unification failures if some
unrelated arguments later unify.

Fixes #465
Update version number
Merge pull request #486 from david-christiansen/color-repl

Keep colour theme on REPL reload
Merge pull request #487 from tauli/master

SimpleParser: improving performance so it is usefull for real world stuf...