fix($state.go): param inheritance shouldn't inherit from siblings

Due to a bug in the ancestors() function, we were treating any states at the same depth from root as "ancestors". This means siblings were inheriting parameters from each other. Interestingly ui-sref generated the correct links, but the click handler then broke the link.

Unfortunately this is a breaking change if someone depends on the broken behavior of inheriting all the params on sibling state transitions. The fix for these folks is mostly simple: create a common parent state that contains parameters that need to be shared. Unfortunately it can introduce quite a bit of churn in the codebase.
Merge pull request #719 from mikekap/param_inheritance

fix($state.go): param inheritance shouldn't inherit from siblings