RavenDB-2174: Some code refactoring around WebSocketsTransport
RavenDB-2174: some more code refactoring
Merge branch 'master' of https://github.com/ayende/ravendb into RavenDB-2174

Conflicts:
	Raven.Database/Server/AppBuilderExtensions.cs
RavenDB-2174: some code refactoring, started implementing new "watchTraffic" UI
RavenDB-2174: implemented watchTrafficConfig
RavenDB-2174: implemented basic watchTraffic
changed isActive class to 'pressed' and moved it to a common place in app.less
RavenDB-2174: Watch Traffic UI progress
RavenDB-2174: finished writing watchTraffic ui, before merging into the management view
preparing RequestManger for merge
RavenDB-2598 RavenDB failing test
attachment exports should be a 2-step process, first metadata should be downloaded, then for each attachment we should download data, not all at once
reintroduced IServerStartupTask
Better file names
Better log entries
Merge branch 'master' of https://github.com/ppekrol/ravendb
RavenDB-2501 custom functions must perform validation against jint mechanism before saving
Merge branch 'RavenDB_2501' of https://github.com/ml054/ravendb
Including stable / not stable in the CommonAssemblyInfo.cs
Merge branch 'master' of https://github.com/ayende/ravendb into RavenDB-2174

Conflicts:
	Raven.Abstractions/Data/ChangeNotification.cs
	Raven.Database/Server/WebApi/RequestManager.cs
	Raven.Studio.Html5/App/common/httpTraceClient.ts
	Raven.Studio.Html5/App/viewmodels/logs.ts
	Raven.Studio.Html5/Content/app.css