Fixes: U4-581 Automatic publishing not working in load balanced setup - added some more convention and configuration to distributed calls so that servers are aware of the master and how to call into themselves for scheduled tasks, ping and scheduled publishing. Will need to update the docs on LB regarding this too. Cleaned up the code that does the scheduling and separates it into proper segments. Obsoletes the old presentation classes that were doing it.
fixes url returned in GetCurrentServerUmbracoBaseUrl
adds authorization to the scheduled publishing , this new attribute can be used to secure scheduled tasks as well.
Merge remote-tracking branch 'origin/6.2.1' into 7.1.5

Conflicts:
	src/Umbraco.Core/Umbraco.Core.csproj
	src/Umbraco.Web/LegacyScheduledTasks.cs
	src/Umbraco.Web/Umbraco.Web.csproj
	src/Umbraco.Web/WebBootManager.cs
	src/Umbraco.Web/umbraco.presentation/publishingService.cs
adds logging to scheduled bits
fixes merge issue
Merge branch '7.1.5' of https://github.com/umbraco/Umbraco-CMS into 7.1.5
Merge remote-tracking branch 'origin/6.2.1' into 7.1.5
Ensures the 'Index' portion of the path is used for scheduled publishing
adds some notes
another log
Merge remote-tracking branch 'origin/6.2.1' into 7.1.5
ensures timer's are not GCd
updates state param with timers to use singleton
Merge remote-tracking branch 'origin/6.2.1' into 7.1.5
last issue with state/keep alive timer
Merge remote-tracking branch 'origin/6.2.1' into 7.1.5