changed wording
edited some problems that use parserImplicitPlane
embedded videos in 20/60/65 set headers
Merge branch 'develop' of /opt/webwork/courses/yao-LibDev/templates/local/PCC into develop
more editing of problems using parserImplicitPlane.pl
embedded videos to a mth 60 header
Merge branch 'develop' of /opt/webwork/courses/yao-LibDev/templates/local/PCC into develop