Fixed login tests

Major change is the logical OR-ing of locators in the flash region;
the login page flash_div was never being looked for based on my
selenium logging.

Minor changes:
- Login and logout are combined into one test
- Bad password test now expects the error being raised by a failed login
- user dropdown moved to dashboard, since it isn't visible on the login page
- dashboard gets an identifying_loc
This guy (`div#flash_div`) wasn't showing up in my selenium logs. Rather than track down what weirdness might be happening with the string concatenation, I just made this more explicit. I also made some indentation changes so that I could read it without going crosseyed.