CanCOGeN specification package v2.5.2

Contents:

Field and Term Reference Guides 2.5.2
Curation Standard Operating Procedure (SOP) 2.5
New Term Request Standard Operating Procedure (SOP) 2.0

Updates:

Field	Change
sample collected by	New term IDs and definitions
sequence submitted by	New term IDs and definitions

Updated curation guidance to support addition of new fields.

Details can be found under release notes issue #4