(Providers) Initial commit
Merge branch '2.x' into feature/components
Implemented ProviderManager (incomplete)
(Providers) Work in progress
* Combined most discount rule plugins in a single plugin: SmartStore.DiscountRules
* Moved both exchange rate provider to the core and deleted correponding plugin projects
Merge branch '2.x' into feature/components
Further ProviderManager changes (incomplete)
Several performance optimizations
Changed plugin project's web properties to use a custom server (prevents multiple IISExpress processed from being started)
(Perf) Added property AutoAttachEnabled to IDbContext. If 'false', entities created by stored procs do not get attached to the ObjectContext anymore (useful for long running processes like catalog export)
(Perf) New property IDbContext.ForceNoTracking: ensures that IRepository<T>.Table always returns an 'AsNoTracking()' query. Perfect for long running processes (like export), where large data sets get queried from the database.
(Perf) web.config runAllManagedModulesForAllRequests is 'false' now. Added a bunch of new web.config files to serve static content explicitly. Also moved plugin meta image files like icon.png or branding.png to the 'Content' subfolder. Theme preview files are also affected and also had to be moved.
Routing: (perf) reduced and simplified mvc routes
* (Perf) drastically reduced amount of routes, accompanied by reorganizing them (removed ~80 routes, now we have ~50 routes in SmartStore.Web)
* (Perf/Dev) Heavily reorganized CatalogController by moving product detail specific actions to the new ProductController, alongside with moving the corresponding views
Admin: product edit partials now load deferred per AJAX (incomplete)
Optimized admin navbar (icons & stuff)
Made all model validator classes partial (although it's useless at this point, but there is more to come...)
* (UI) AJAXified product edit tab: all tabs other than the first one load on demand per AJAX
* (Developer)  Plugins can provide custom tabs more easily (now with on demand AJAX loading)
* (Developer) Model binding for plugin tab views: models from plugin tabs get automatically materialized and bound to TabbableModel.CustomProperties[MyKey]. Extended the SmartModelBinder for this.
* (Developer) New event ModelBoundEvent. Consume this in plugins to persist plugin specific models.
* (Admin) Added 'GMC' tab to product edit view. This is more a coding example for the above stuff rather than a new feature.
* (UI) optimized and reorganized product edit view a bit
Merge branch '2.x' into feature/components

Conflicts:
	src/Plugins/Api.WebApi/Description.txt
	src/Plugins/Feed.Froogle/Controllers/FeedFroogleController.cs
	src/Plugins/Feed.Froogle/Services/GoogleFeedService.cs
	src/Plugins/Feed.Froogle/Services/IGoogleFeedService.cs
	src/Plugins/Payments.PayPalStandard/Description.txt
	src/Plugins/Shipping.FixedRate/Description.txt
	src/Presentation/SmartStore.Web/Controllers/CatalogController.cs
Updated changelog
Minor merge fixes