description of comments in language.md
updated readme + part-1 descriptions
description for part 2
description for part 3
comment about reading test descriptions in parts/1.md
description for part 4
description for part 5
description for part 6
renamed 'car' and 'cdr' to 'head' and 'tail'
description for part 7 (unfinished)
fixed so run-tests.sh aborts after first run when inotifytools is missing