Merge pull request #406 from mtbc/americanize-spellings-dev

Americanize spellings, fix typos, expand contractions (rebased)
Adding What's new sections ticket 11177
merge develop -D org -I include -E exclude: PR 369 (Cpp: Correct content and markup)
merge develop -D org -I include -E exclude: PR 404 (Updating Download screenshots for Version 5 (FS))
merge develop -D org -I include -E exclude: PR 408 (Adding What's new sections )