Support for multiple global task filters and/or filter tasks queries by tags

[devinbaillie]

I'd like to be able to sort tasks by multiple tags (#task, #habit, #waiting, #shopping, etc.) and use tasks queries to find all the relevant ones based on tags and have the option in the tasks queries or the plugin settings to hide the tags, set completion date, etc for each tag separately.

If I'm working on a document for a project, and I want to add a task, then I would tag it with #task, and if I think of something I need to buy for the project, then I could tag it with #shopping, and I can have a global manager for all of my to-do items, and a separate manager for my shopping list. Then next time I'm at a store, I can quickly check the shopping list to see whether I need anything that I can pick up at that store.

I can do the lists with Dataview (and this is what I do now), but can't easily hide the tags in the lists and it won't add completion dates if I check off tasks on the page they actually exist on, rather than on the dataview list.

[claremacrae]

@devinbaillie Filtering by tags was released in 1.6.0.