test suite broken

[FND]

there's all sorts of errors when trying to run the test suite in a vanilla repo (tested on both OS X and Debian, with Node v0.10 as well as v0.12):

1. test/credentials.js is required, but missing (explicitly excluded in .gitignore)
2. "TypeError: Cannot read property 'app' of undefined" in test/test_dropbox.js)
3. various relative paths don't work:
   1. "Error: Cannot find module '../../jsdav'" in lib/DAV/backends/ftp/tree.js
   2. "Error: Cannot find module 'jsdav/lib/DAV/plugin'" in test/test_multi_instance_plugin.js
4. "Error: listen EADDRINUSE" (after temporarily deleting the two problematic test files above)

I eventually gave up before descending deeper down the rabbit hole, meaning I unfortunately can't tackle #119.