documented new features and added new screenshot for mplotqueries.
documented new features and added new screenshot for mplotqueries.

corymintz/mtools,rueckstiess/mtools,devkev/mtools,aerrami/mtools,gormanb/mtools,parkhyeonghwa/mtools,yaowenqiang/mtools,tomzhang/mtools,gormanb/mtools,tomzhang/mtools,aerrami/mtools,corymintz/mtools,aerrami/mtools,yaowenqiang/mtools,gormanb/mtools,corymintz/mtools,devkev/mtools,rueckstiess/mtools,ces0712/mtools,parkhyeonghwa/mtools,tomzhang/mtools,yaowenqiang/mtools,parkhyeonghwa/mtools,devkev/mtools,ces0712/mtools,ces0712/mtools