Fix the display of formulas in the manual on systems where UTF-8 is not the default encoding.

This release includes work done by Lourens Elzinga, Rik Timmers, and Wouter Reckman to extend OOPS to many new modal logics. They also added syntax highlighting to the Lua editor. Gert van Valkenhoef did some improvements and clean-up, added a help system / manual, and delayed the release by a huge amount (sorry!).