Full compliance with HTTP RFC nomenclature

[lfcipriani]

HTTP clients should be compliant with the nomenclature established by the HTTP RFC [1, 2]. This issue addresses the verification of:

• Messages: Request, Response
• Headers: Field Name, Field Value
• Body: Message body vs Entity Body
• URI/URL
• etc...

[1] http://www.w3.org/Protocols/rfc2616/rfc2616.html
[2] http://www.w3.org/Protocols/rfc2616/rfc2616-sec1.html#sec1.3