Consolidate callGAPIpages() implementation and add docstrings on all GAPI execution-related methods (#851)
Consolidate callGAPIpages() implementation and add docstrings on all GAPI execution-related methods (#851)

* Consolidate callGAPIpages() implementation and add docstrings on all GAPI execution-related methods

callGAPIpages was previously broken out into a few subroutines which contained a couple lines of code and weren't being used elsewhere in the code. The main "GAPI" execution methods were also missing documentation which made it hard to tell what they did and/or how to use their parameters.

* Fix oauth2client library name

GAM-team/GAM,GAM-team/GAM