Adding `ESSearchBuilder`.

This class is responsible for taking the data filter, sort comparison, and
any other required data and turning that into a JSON elastic search
object.

See #24
Adding elastic search values as xml.
Adding ESSearchBuilder bare bones tests.

Not everything has been tested yet. Just the base EQUALS and NOT_EQUALS
cases.
Adding Jest project and other Network dependencies.
Adding libs for jest-droid.
Improve ESSearchBuilder tests.
Adding GsonTypeAdapters and continuing NetworkDataManager.
Adding type filter implementation and NetworkDataSourceTest.
Updating names of stock test ES elements.

Updating the field names in the elements used in automated test cases against the ES test server.
Adding `INTERNET` permission to AndroidManaifest.

So that we can talk on the interwebs.
Implementing Object.hashCode() and Object.equals() for QAModel and UniqueId.
Adding method to get item type enum from string.
Add Sort Direction support to comparator interfaces.

Comparators can now have the sort direction specified to be `Ascending` or `Descending`.

Also added a `getFilterField()` function that returns the name of the field that the comparator sorts on.

Closes #72
Fixing body text in test answer.
Updating `DataFilter` and `ESSearchBuilder` to support paging, max results.

The `ESSearchBuilder` now returns the search builder object, after adding any neccesary parameters to it that cannot be communicated in the query body.

`DataFilter` is now how paging and result limiting is performed.

See #24
Updating `IncrementalResult` for new IItemComparator implementation.
Fixing deserialization for AuthoredTextItems and adding field names.

Model classes name have static final field name attributes, containing the string names of each of their fields.
Adding more comprehensive ESSearchBuilder tests.

Supports pretty much everything except validating against an elastic search server.

See #69
Adding NetworkDataManager implementation.

Most functionality, along with availability and data item loaded notifications have been implemented.
Fixing Jest project. (Removing slf4j dependency).