RavenDB-2922 Failing test: RavenDB_2209.LazyLoadResultShouldBeUpToDateEvenIfAggressiveCacheIsEnabled
Fixing multi get handling

Conflicts:
	Raven.Client.Lightweight/Connection/MultiGetOperation.cs
Merge pull request #1575 from ppekrol/2.5

applied 3.0 fixes to 2.5
Merge pull request #567 from ayende/2.5

2.5