RN 12/3/2014
Merge pull request #41 from edx/markhoeber-doc1254

First draft RN 12/3/2014
Add wiki info to student-facing documentation
Merge pull request #46 from edx/sylvia/docs/DOC-1132

Sylvia/docs/doc 1132
EdX Vudeo ID field description in main B&R guide
Reorg of cohorts and discussion topics
Excludes changes for always-cohort-inline-discussions (DOC-1077)
Merge pull request #48 from edx/carol/docs/DOC_cohorts

Reorg of cohorts and discussion topics
First draft
Edits per review comments
Fix formatting error after rebase
Updated links to new edX101 course
Merge pull request #50 from edx/ahodges/edX101

Updated links to new edX101 course
Added edX101 to preface
Updates per reviews, further conversations

Also removed redundant note about username and email checking
Fix wording re comma requirement in csv
Changes to column requirements description
Further edits from review comments
Merge pull request #51 from edx/ahodges/preface

Added edX101 to preface
Further edits from review comments
Add preface; add topic list to Introduction section