automatically fetches nltk corpora and builds nlm
Squashed commit of the following:

commit 0a987341157857ab34887a128e0a50d0a6d904b2
Author: Conor Schaefer <conor.schaefer@gmail.com>
Date:   Wed Jun 25 10:18:58 2014 -0400

    makes bootstrap script runnable from anywhere

commit 55e100cd9736080030685f9f3733a18fa0d38322
Author: Conor Schaefer <conor.schaefer@gmail.com>
Date:   Wed Jun 25 00:15:31 2014 -0400

    figures out SRILM bin path, scraps /usr/bin/env

commit 1c23e21955d2fa8a6ab7f78782156db51664b3e5
Author: Conor Schaefer <conor.schaefer@gmail.com>
Date:   Sun Jun 22 15:32:56 2014 -0400

    makes all bootstrapping conditional

commit 6c677a051bb6dab37312d6acdc0fa657d0a412ae
Author: Conor Schaefer <conor.schaefer@gmail.com>
Date:   Sun Jun 22 14:52:30 2014 -0400

    adds punkt tokenizer to download list

commit 18b46df653d8b2cdd5681d153f3be5ea98cabead
Author: Conor Schaefer <conor.schaefer@gmail.com>
Date:   Sun Jun 22 14:50:00 2014 -0400

    adds hard-coded download dir