add support for tasks (both command and reporter)

bumps NetLogo version to get changes to compiler (lambda-lifting
moved from front to middle end) and some additional tests
Merge pull request #76 from NetLogo/tasks

add support for tasks (both command and reporter)
TestModels now compares actual to expected JS

this may help catch regressions in the compiler. but it's also
useful for us to have a corpus of models in JavaScript that
we can look through or grep, for all sorts of reasons
fix a tiny regression in JS generation

a semicolon went missing when I was cleaning up