Throttle the number of concurrent non-anonymous requests
Add cloudwatch metric for throttling
Merge remote-tracking branch 'upstream/develop' into PLFM-1174

Conflicts:
	client/synapseJavaClient/src/main/java/org/sagebionetworks/client/SynapseAdminClient.java
	client/synapseJavaClient/src/main/java/org/sagebionetworks/client/SynapseAdminClientImpl.java
	services/repository/src/main/java/org/sagebionetworks/repo/web/controller/AdministrationController.java
	services/repository/src/main/java/org/sagebionetworks/repo/web/service/AdministrationService.java
	services/repository/src/main/java/org/sagebionetworks/repo/web/service/AdministrationServiceImpl.java
Merge remote-tracking branch 'upstream/develop' into PLFM-1174
adjust test for new synapse client behaviour
Merge pull request #1292 from marcel-blonk/PLFM-1174

Throttle the number of concurrent non-anonymous requests