Update SFU API to use classType if section is lab/tutorial

classType of 'e' => "main section"
classType of 'n' => "lab/tutorial section"
Use associatedClass from SFU REST to determine tutorial/lab sections

associatedClass now available as part of the SFU REST call for '../rest/course/course.js'.

This should be more reliable vs pattern matching for section name.
Only check/return 'child' sections for enrollment sections

Tutorial sections (e.g. D101, D202) and Lab sections (e.g. (LA01, LAB1) should not have any child sections.
Added to code to check for tutorials and labs for non-enrollment sections

Since any sectionCode can be used for enrollment and non-enrollment, we have to create our own priority setting list. Currently we only know of tutorials and labs.

So code now checks to see if an enrollment section has any tutorials and labs. If it has both, only get the the tutorials, else take all of the non-enrollment sections.
Removed whitespace and cleaned up the code with Andrew's help
1 more syntax fix

Sometimes it's not worth it trying to clean up the code
Merge pull request #173 from ronvs/rs-sfu-rest-update-classType

Update SFU API to use classType if section is lab/tutorial