Update context config options
Update context config options

- options grouped under "context"
- added option to activate "greedy" context gathering

Dark5ide/mycroft-core,MycroftAI/mycroft-core,MycroftAI/mycroft-core,Dark5ide/mycroft-core,linuxipho/mycroft-core,forslund/mycroft-core,forslund/mycroft-core,aatchison/mycroft-core,linuxipho/mycroft-core,aatchison/mycroft-core