Add examples of how to use factories in the documentation

[glassfishrobot]

See this thread on stack-overflow concerning the lack of documentation on the use of factories:

http://stackoverflow.com/questions/20123326/how-do-i-configure-hk2-to-inject-an-object-created-by-a-factory-method

Affected Versions

[2.2.0]

[glassfishrobot]

• Issue Imported From: https://github.com/javaee/hk2/issues/211
• Original Issue Raised By:@glassfishrobot
• Original Issue Assigned To: @jwells131313

[glassfishrobot]

@glassfishrobot Commented Reported by @jwells131313

[glassfishrobot]

@glassfishrobot Commented This issue was imported from java.net JIRA HK2-167