argument order
restoring checkPositionContaininment, and fixing the underlying bug in
the parser that discarded the possibility of rules whose first item is
a nulled production -- then it wouldn't include the correct span information
tests in pyret
Merge branch 'new-world' of github.com:brownplt/pyret-lang into new-world
test strings a bit
fixing the unneeded message that we get when parsing the empty string
-- my implementation differs slightly from the RNGLR paper, in that we
always explicitly shift the EOF token, so we don't have to worry about
the completely-empty case, I don't think.
fixing erroneous JS output of scientific-notation number printing
making 'make test' work again: more generative-structs problems with
js-numbers.  also eliminating a stray console.log
image equality for opaques
add safeTail and use it for built-in callback prims
increment after call and provide to clients
forgot this with other img commits; layers for generating gif
start pulling out errors into common structs defined in error.arr
skeleton of code for a separate, visual check mode display, and make check-block-result not lie about names
more pleasant api functions for runtime
(hopefully) minor bugfix to command-line arguments library, such that once it finds a single argument that isn't a value for the known options, it stops processing, so that the remainder of the command line can be passed along to a nested program, perhaps.
paths...
silly non-use of the options...
test-errors
Merge branch 'new-world' into for-bootstrap

Conflicts:
	src/web/repl-ui.js