Add missing lang attributes for improved accessibility (see http://www.w3.org/TR/UNDERSTANDING-WCAG20/meaning-doc-lang-id.html and http://www.w3.org/TR/WCAG20-TECHS/H57.html).
Merge pull request #3139 from danielnixon/master

Add missing lang attributes for improved accessibility
fix javadoc indent
Merge pull request #3142 from gmethvin/json

fix javadoc indent
Simplify json response example and add an example of serializing a Java object
Merge pull request #3144 from benmccann/json-docs

Simplify json response example and add an example of serializing a Java object