[dfmc,projects] Allow callers of build-project to enable fatal warnings.
Merge pull request #714 from waywardmonkeys/wfatal-prep

[dfmc,projects] Allow callers of build-project to enable fatal warnings.
[dylan] Fix comment/string typos.
Try to improve text about gc-path.
Cleanup comments, parameter list formatting, and capitalization.
Remove commented-out code to lex conditional compilation directives.
Initial pass at triple-double multi-line string parsing.
Initial dfmc-reader-test-suite