Update all projects to 4.7.2

[MarkZither]

To prepare for migrating to new csproj and .net standard libs update all projects to 4.7.2

[MarkZither]

compare with screwturn codeplex archive v4 branch at the same time. Plugins

• [x] ActiveDirectoryProvider
• [x] DownloadCounterPlugin
• [x] DownloadCounterPlugin-Tests
• [x] FootnotesPlugin
• [x] MultilanguageContentPlugin
• [x] PluginPack
• [ ] RatingManagerPlugin - migrated to new csproj and 4.7.2 but need to complete merge with v4 branch
• [x] RssFeedDisplayPlugin
• [x] SqlProvidersCommon
• [x] SqlProvidersCommon-Tests
• [x] SqlServerProviders
• [x] SqlServerProviders-Tests
• [x] UnfuddleTicketsPlugin

Core

• [x] AclEngine
• [x] AclEngine-Tests
• [x] Core
• [x] Core-Tests
• [x] PluginFramework
• [x] SearchEngine - migrate code from v4 for lucene
• [x] SearchEngine-Tests
• [x] TestScaffolding
• [ ] WebApplication

[MarkZither]

remaining work split out into separate issues as they are larger pieces of work.

[MarkZither]

8 complete