Removed obsolete TODO comments relating to failing tests that now pass on mono 2.10.11
Removed ResponseCache logic from DreamService and dependent types.
Removed unused local variables.
Disabled warning for unused local variables (CS0219)
Disable warnings for unused local variables (CS0219) and unused object fields (CS0414) in test projects.
Replaced all occurrences of delegates with lambdas.
Removed unnecessary call to Confirm() in WhenDone().
Added back <TargetFrameworkVersion>v4.0</TargetFrameworkVersion> to .csproj files.
Merge branch '2.4_replace_delegates_with_lambdas' into DR-105

Conflicts:
	src/mindtouch.core/DreamHostService.cs
Merge remote-tracking branch 'bjorg/DR-105' into 2.5