The Denver Campaign for Limited Social Use submitted more than 10,000 signatures Monday in support of a city initiative that would allow the limited social use — but not sale — of marijuana at commercial establishments in areas restricted to adults 21 and older. 4,726 valid signatures of registered city voters are needed to qualify for the November 2015 ballot. The city clerk has 25 days to certify the petition. Under the proposed measure, businesses that have a license to sell alcohol for onsite…