Isolate CSV builder code into separate class
Simplify section_csv method

Eliminate `unless cross_list` statement by enumerating where the
section_csv method was called, instead of calling it recursively.

Simplify logic that determines when a section is added to the array, by
using `next` to skip, instead of multiple if/elsif statements.

Eliminate the need to join and split section info parts using ":_:".
Use the CSV module to build the output

The CSV module automatically escapes commas and quotes, so we don't have
to worry about it.
Reduce overall visual clutter

* Convert hash key strings to symbols
* Use single quotes to delimit simple strings
* Group .upcase calls
* Use local variables in instance methods whenever possible
* Eliminate redundant variables and delimiters
Define spec for CSVBuilder

56 examples and 8 pending
Merge pull request #133 from va7map/canvas212-refactor

Fix and refactor Start a New Course form