[#42674731] Updated provider to read from legacy path as well

For clients with outdated serialization policies, read from
the original google cloud storage location
Refactored TempStorageProvider to use the BlobService
for storage and to read the host name from the config
(key = base.uri)

This way maps etc generated during a task request
will have the correct url
[#45374001] Properly segregate staging environment
[#43120355] Email digest: layout, tests, some textual changes and
grouping on date by the last 24 hours instead of from midnight on
Merge branch 'staging' of github.com:bedatadriven/activityinfo into staging
Merge branch 'staging' into production

Conflicts:
	server/src/main/java/org/activityinfo/server/endpoint/gwtrpc/CommandServlet.java
merging