Fix autotest issues watching multiple directories

Multiple directories would mean multiple watches being applied
to the same pathspec. As glob was an array, the watches covered
all paths, just multiple times.  Removed a TODO to refactor as
it's no longer quite so ugly.
Added --watch option to watch additional source paths with --autotest

Previously it was only possible to watch the same paths as the specs
were in.  Now with --watch, you can have your specs and your source in
separate directories, and watch the source for changes. Changes to the
watched directories will always cause all tests to be run.
Added note in README.md about --watch
Preparing for 1.8.0 release
Merge branch 'master' of github.com:mhevery/jasmine-node
Updated test count
Updated specs.sh to be less verbose