by default, run all tests during npm test, and emit clear errors when dependencies (mysql or phantomjs) aren't installed

run mysql tests *first* (they're more important), and if we can connect to db but browserid table doesn't exist, we still have db connectivity and can run tests

make npm test work right.  improve test.sh to ensure it's using the version of vows that the package is locked to and works both when invoked via npm and from cmdline

top level test.sh file now tests to see if we can connect to the database before running tests for that environment.  issue #171

a little test script to allow for running of all tests in repo from top level, also hopes to make tests more discoverable