Change importer to use saved object class, fix broken select all

[lukasolson]

Closes #3912, #4311, and #4508,

Prior to this, the import functionality would work by reading in the uploaded file then creating a simple bulk request to the .kibana index.

While this seems good and all, it caused issues, such as this: #3882.

What happens behind the scenes, is that when importing, if we don't use the saved object classes, then certain values (such as hits and version) can get mapped to an incorrect type (long instead of int, etc.).

This PR addresses this by utilizing the saved object classes when importing. Basically, how I accomplished this was by taking the applyESResp function out and separating it, so that it could be used from outside the loading of an object. When an import happens, we use that function to load the objects as if we were loading them directly from an ES fetch, so all of the magic that usually gets applied can get applied in this step.

Also part of this PR is fixing the select all functionality, which was broken because $scope.currentTab wasn't being set initially if it was explicit in the URL.

[w33ble]

You can use Promise.map, which uses Promise.all internally

[lukasolson]

Delicious.

[w33ble]

There's an issue with the importing, which may not be related to this PR.

• Do an import and it would overwrite an existing object
• Select cancel at the prompt
• Try importing again, and this time nothing happens

[w33ble]

This looks good to me, passing on for last looks. @lukasolson do chime in on that import cancel issue though.

[lukasolson]

This was due to the fact that we use an onchange handler, and if you upload the same file twice, it doesn't fire the onchange handler (since it didn't change). Resetting the value on click seems to solve this though. I've added a fix for it.