First example that produces something "close" to working
 Also added error messages
Made new stencil access syntax, i.e., u(i, j) instead of u[[i, j]]. Does
not work yet
 The current version does not get function definition scopes correct,
because I have removed the rule from the parser (otherwise I got a
shift/reduce conflict). The best approach to solve this might be to have
a meta-node which handles all function call-like
Should reproduce existing (non-stencil) compilations
 Not checked, and stencils do not work yet
Compiling stencils now works
 However, not all of the error checking appears to work. Need to
investigate a bit further.
Appears to work well with stencils