issue fixed: RavenDB-2163
used NProgress prgress bar and spinner to "inform" user about loading (when loading time is between 1sec and 10 sec)
used error message to inform user that waiting time is too long (when reaching 10 sec mark)
Merge branch 'master' of https://github.com/ayende/ravendb
Merge branch 'master' of https://github.com/grisha-kotler/ravendb
Merge branch 'master' of https://github.com/grisha-kotler/ravendb
started implementing metrics for Counter Storage
first version of counters client api
Merge branch 'master' of https://github.com/maximburyak/ravendb
counters metrics from storage to controller progress
Merge branch 'master' of https://github.com/ayende/ravendb
Client API for managing counters
Merge branch 'master' of https://github.com/ayende/ravendb
scripted index not showing fix
Get and save replications for counters Client API
counter stats: finished server side + controller of counterStorage stats, metrics and replication stats
Merge branch 'master' of https://github.com/grisha-kotler/ravendb

Conflicts:
	Raven.Database/Counters/Controllers/CounterReplicationController.cs
	Raven.Database/Counters/Controllers/CountersController.cs
	Raven.Database/Counters/CounterStorage.cs
removed unnecessary code from RavenCountersClient.cs
Merge branch 'master' of https://github.com/grisha-kotler/ravendb
included excluded voron tests
fixed ItemCount test in voron
fix issue RavenDb_2324 - show document metadata size in kb