Early-voting signs went up this week for the Nov. 8 election on 10 proposed amendments to the state Constitution. Lawmakers crafted the propositions during the legislative session, and now it’s time for voters to weigh in on such issues as funding of water projects, student loans, agricultural exemptions and rules for officeholders. The 135 year-old Constitution has been amended almost 500 times, and most amendments usually pass. Historically, turnout in these elections is low — less than 20 percent.