Merge pull request #194 from selwin/master

Job.create should allow args to be passed in list format
Made rqworker and rqinfo respect db parameters from --url

When starting the rqworker and rqinfo scripts with an --url parameter containing a non default database, e.g. redis://localhost:6379/2, both scripts connected db 0 instead of the desired database. Fixed this behavior by ignoring the --host, --port and --db arguments if --url is there.

Also fixed another issue with the rqinfo script, in which it defaulted to only the 'default' queue instead of finding all available queues using Queue.all().
Merge pull request #198 from johannth/scripts-respect-url

Made rqworker and rqinfo respect db parameters from --url
extract `safe_fetch_job` method
get a page of jobs
Minor refactoring of the paging logic.
Fix typo.
Update changelog.
Replace the Calculator fixture by a Number fixture.

This makes the tests a little more realistic, since I want to add a test
for class methods.
Add explicit classmethod test.