bstart building challenges
challenges: fix up lists to use new list templates
challenges: list taken dynamically from scope so we can push/unshift to various task lists depending on location of add-task form. be careful with this commit, not the {{}} instead of {} - seems to be required otherwise things get weird
challenges: add assignTo option on challenge-creation
challneges: semi-functional challenge creation for parties
challenges: basics for challenge subscription
challenges: chevron in collapsing title
challenges: add challenge.id to task so we can get the icon-bullhorn
challenges: prevent some task options (such as scoring, check-marking,
tags, etc) for challenge edits
challenges: fix to not apply user's active tags to new challenge
tasks, but also not apply filters except to main user's list
challenges: require challenge title, when user subscribe add new tag of challenge name. unsubscribe deletes tasks
challenges: migration & store: rename parties to groups, create habitrpg guild, move tavern into habitrpg, overhaul of motifs and subscriptions
challenges: fix up htmls to use new party-member subscription methods
Merge branch 'develop' into challenges-tmp

Conflicts:
	src/app/helpers.coffee
	src/app/index.coffee
challenges: rename party.html to groups.html
guilds: bug fix on _tavern => _habitRPG
guilds: got all groups html generalized (using same party html as
tavern, will add guilds soon)
guilds: rename party.coffee => groups.coffee
guilds: generalize more groups stuff, creation invitation leaving,
etc. also fixes party invite bugs
guilds: html & store.coffee bug fixes