[vis/editor] enable time filter when appropriate
[vis/editor] only allow selection of enabled options
[vis/editor] remove kbnValidOptions directive, use null option
[agg/dateHisto] only apply extended_bounds if the indexPattern is time based
Merge pull request #1657 from spenceralger/fix/1656

Update visualize for non-time-based indices
Send time filter as a number to avoid mapping issues. Closes #1558
Use same protocol for elasticsearch as everything else. Closes #1586
Merge pull request #1680 from rashidkpc/fix/elasticsearch-endpoint-protocol

Use same protocol for elasticsearch as everything else. Closes #1586
Merge pull request #1679 from rashidkpc/fix/timefilter-as-number

Send time filter as a number to avoid mapping issues. Closes #1558