Don't double-transition on child states with no URLs

[nateabele]

I found this issue while trying to finish up the ui-sref directive.

Basically, if a state has a URL, but a child state does not, it is impossible to transition to the child state, because the change in location will immediately trigger a second state transition to the parent. This fixes the issue by checking to see if the current state is a child of a state being targeted for transition based on a URL match.

Also fixes a typo in a test name. :-)

[nateabele]

@ksperling If I can get a review of this, it should be the last change needed to finish implementing and testing ui-sref.

[ksperling]

Good catch! See my comment in the code regarding the particular check though... I think we need to check for $state.$current.navigable != state.

[nateabele]

@ksperling Yeah good call. I've updated the patch. Go ahead and merge if it looks good.