Merge pull request #84 from paulvojta/master

Numerous bug fixes and improvements
Library "static" tags
Merge branch 'master' of github.com:openwebwork/webwork-open-problem-library
Resize one graphic

The tex_size=>700 option scales the graphic to be 70 percent of the width of the graphic (in pixels?), but this graphics file is tall and thin so it needed to be rescaled by 700 * 68 / 300 = 158.666
Fix division by zero bug
Fix division by zero bug
Resize graphic
Resize graphic
Resize graphic
Add missing \{ EndList("OL") \}
Add missing \{ EndList("OL") \}
Add missing \{ EndList("OL") \}
Add missing \{ EndList("OL") \}
Split long equation list across two lines
Split long equation list across two lines
Split long equation list across two lines
Split long equation list across two lines
Split long equation list across two lines
Add $BR
Break long line in problem text