move stack into repository itself

.gitignore

.gitmodules

Dockerfile

assStackQuestion

bin/web

build.sh

buildimage.sh

goe_web

maxima_version

moodle-qtype_stack

moodle_version

sbcl_version

stack/2014083000/maxima/arccos.lisp

stack/2014083000/maxima/assessment.mac

stack/2014083000/maxima/assessment.texi

stack/2014083000/maxima/complexi.lisp

stack/2014083000/maxima/complexj.lisp

stack/2014083000/maxima/cos-1.lisp

stack/2014083000/maxima/elementary.mac

stack/2014083000/maxima/expandfeedback.mac