Convert spaces to tabs in all go code

Converting tabs to spaces is no longer supported by gofmt since go1.3.
Thanks, Brad... https://code.google.com/p/go/issues/detail?id=7101
Extract a call to blackfriday into its own func
Sanitize html with bluemonday

Call blackfriday without sanitization and sanitize html separately, with
bluemonday. Sanitize comments from random people with generic settings,
but give my own content some liberty.