- use ® instead of ® in html templates - seems to work better with
  doxygen at the moment

- avoids them showing on related pages

- slightly better memory efficiency and file sizes
- consistent with library reader

This makes the solver more robust when the "Courant number" of the flame
propagation fluctuates.

- change from 'kde-open %f' to the desktop-agnostic 'firefox %f' as
  the default document browser.

- a holdover from the old <root> <case> days

Slip bc can now be used on non-constraint patches