Replace 1 author in AR2 WGII Ch17 (same last name but different)

* 1 LA author: "K.M. Clark"
Add short extract of chapter 18 with authors information
Merge branch 'master' into qa (add missing source for AR2 WGII Ch18)
Replace 2 authors in AR2 WGII Ch18

* 2 CA authors: "R. Anderson" (incompatible first name initial),
                "I. Galindez Giron" (OCR misspelling)