While fetching from ingest archive_ingest fails to insert initial version of the document in archive_versions.

Analysis:

Versioning is not enabled for Ingest resource and also resource definition has no projection attribute. While registering Ingest resource with domain, flask adds default projection to Ingest resource. Default projection will have the fields specified in schema attribute. Because of this querying on Ingest resource will not return "_version" as part of response even though the collection has that attribute, Because of missing "_version" attribute archive_ingest fails to insert document into archive_versions.

Solution:
Although versioning wasn't enabled for Ingest resource, superdesk inserts "_version" attribute. This is removed and inserting "_version" attribute while fetching. Also modified behave tests of fetching in archive_ingest.feature to check for "_version" after fetching.
SD-1286 Add key to store selected theme in user preferences.
Merge pull request #465 from amagdas/sd-1286

SD-1286 Add key to store selected theme in user preferences.
Merge pull request #464 from sivakuna-aap/fetch_fails_to_create_version_history

While fetching from ingest archive_ingest fails to insert initial version of the document in archive_versions.
Moved DAYS_TO_KEEP to environment variables
[SD-1268] API: Rename the end point for saving the search
[SD-1269] Backend: Make sure the search criteria is saved without the context
[SD-547]  Delete a saved search
[SD-548]  List saved searches
Adding copyright information
[SD-1268] API: Rename the end point for saving the search
[SD-1269] Backend: Make sure the search criteria is saved without the context
[SD-547]  Delete a saved search
[SD-548]  List saved searches

Modified resource_title of /saved_searches not to inherit from url.
[SD-1268] API: Rename the end point for saving the search
[SD-1269] Backend: Make sure the search criteria is saved without the context
[SD-547]  Delete a saved search
[SD-548]  List saved searches

Modified as per comments in PR.