[rootSearchSource] set the default index pattern properly on change
[config] log the proper values on change
[notifier] #event() respects returned vals, and promises
[savedVis] stop tracking the indexPattern
[rootSearchSource] clean up refresh logic
[savedObject] allow get to load values from root sources
[SearchSource] make #getParent() always run synchronously
consolidate code, remove unused _dynamicState
make sure indexPattern get reset if something goes wrong
return undefined or searchSource, not false
code style
Merge pull request #1617 from w33ble/indexPattern/loading-2

Index pattern/loading - after team review