Create SecurityMockMvcResultHandlers to define security related MockMvc ResultHandlers
Create a method to allow copying the SecurityContext from the TestSecurityContextHolder to SecurityContextHolder
Closes gh-9565
I went through everything to get it to fit with Spring's docuemntation standard.
Lots of small changes for punctuation, grammar, usage, voice, and so on.
Also added some links, mostly to the API Javadoc.