The Tags UI needs to be redone


When the user is posting or editing an article the user interface for adding and removing tags sucks (to put it mildly). It should be replaced with a single TextBox where the tags are separated by commas. What is more the code for handling the tags sucks so it will be fixed too. We have to make sure that we allow whitespace between the commas and tags but the whitespace should not be included in the tags. We need to craft a regex to validate the tags separated by commas. We need to add a single space after the comma in edit mode.