CHOP-8. (P1). Chopsticks gets a package object with Scaladocs.

Reviewed by: robertchu
CHOP-8. (P2) ColumnRequest Scaladoc and other revisions.

Revisions are made to Scaladocs for ColumnRequest.scala. InputOptions
is also elevated to the top-level (why should it be nested?) and
renamed to ColumnRequestOptions. Constructors are generally hidden.

Reviewed by: robertchu