Resolve "Helpers should be in a SCL class"

Closes #3 (closed)

added 5 commits

• 4828db39 - correct iterator type
• 8b66570b - put helpers in SclObject class and change constraints to use them
• 9572de5e - correct duplicated constraint names
• 4a870598 - correct forgotten modification to a string test
• 665a9316 - minor modification to error message

Compare with previous version

By Dominique Marcadet on 2018-03-08T08:07:34 (imported from GitLab project)

unmarked as a Work In Progress

By Dominique Marcadet on 2018-03-08T08:07:59 (imported from GitLab project)

mentioned in commit 158520b7

By Dominique Marcadet on 2018-03-08T08:09:37 (imported from GitLab project)

merged

By Dominique Marcadet on 2018-03-08T08:09:38 (imported from GitLab project)