#499: file edit dialog added.
Fixed breadcrumbs holder style.
#499: tags related files moved from pages module to root (build does not work).
#499: categories related files moved from pages module to root (build does not work).
#499: tags and categories related functionality moved from pages module to root.
#499: tags added to files.
#499: tags added to images.
#499: file and image edit dialogs updated.
#501: File edit dialog updated with thumbnail image selection.
#501: file list updated to show thumbnail image instead of icon, if file has it.
#501: thumbnail image location updated on file edit dialog.
#501: thumbnail updated in files list.
#500 Media Manager: added filtering by tags
#500 Merge branch 'dev' of github.com:devbridge/BetterCMS into dev

Conflicts:
	Modules/BetterCms.Module.MediaManager/Content/Resources/MediaGlobalization.resx
	Modules/BetterCms.Module.MediaManager/Models/Maps/MediaMap.cs
	Modules/BetterCms.Module.MediaManager/Models/Media.cs
Merge branch 'dev' into dev-webapi

Conflicts:
	Modules/BetterCms.Module.Blog/Api/BlogsApiContext.cs
	Modules/BetterCms.Module.MediaManager/BetterCms.Module.MediaManager.csproj