Allow excluded keywords

[sqwk]

Allow excluded keywords like this: foo: -bar.

This would be useful especially for something like tags where we user entry like this is entirely possible: tags: this, that, -notThis

{
    "text":["tags: this,  that, -notThis"]
    "offsets":[
        {"keyword":"tags","value":"this","offsetStart":0,"offsetEnd":10},
        {"keyword":"tags","value":"that","offsetStart":0,"offsetEnd":16},
        {"keyword":"tags","value":"notThis","offsetStart":0,"offsetEnd":26, exclude: true}
    ]
}

EDIT: Turns out that this partially possible like this: tags: this, that -tags: notThis, requiring the user to supply the keyword twice.