chore(release): update cdn version
docs(changelog): release notes for 1.2.0
docs(guide/migration): add migration guide
chore(docs): allow periods in doc shortNames
docs(guide/migration): fix link to #2500
docs(guide/migration): fix up internal links
chore(release): update version number for next round of development
feat(ngParse): support trailing commas in object & array literals

Per ECMAScript 5.1 specification trailing commas are allowed in object and
array literals. All modern browsers as well as IE>8 support this syntax.
This commit adds support for such syntax to Angular expressions.