create draft request gets already created version if it exists
STUD-1616
update _xmodule_recurse to ignore some exception
update _xmodule_recurse method
Merge pull request #3766 from edx/zub/bugfix/std1616-editdraft

create draft request gets already created version if it exists
Reorganized, updated, & streamlined sections in Running Your Course
Merge pull request #3818 from edx/ahodges/documentation/DOC368

Ahodges/documentation/doc368