Fix various runtime errors and other miscellaneous things.

Most of these just involve adding `expectConsume` where expressions are expected but a few were slightly different.

9a3e0a8 Previously any expression was allowed on the left side of a bind. I have restricted it to only identifiers and members now which seems to work fine and all the test cases pass, but is this too restrictive?
d29dc60 These runtime errors only appeared in the command-line version of Minigrace, not the JS interface for some reason.
880fcaf The sample programs with includes won't work in the JS UI until they are precompiled to JavaScript, so I've added these precompiled files to .gitignore.