Add support for tracing the HTTP Request/Response flow.

[fatmcgav]

New 'debug' param on NewSession and NewTokenSession funcs.

[scottdware]

Before this one gets merged, can you update the example file (examples\go-bigip_example.go) with the necessary changes? That is what's failing the check(s). Thank you!

[fatmcgav]

Will do...

[kenmaglio]

Instead of adding the debug parameter to the NewSession and NewTokenSession as this would be a breaking change, can we add documentation around the fact that once you get the object back from those two functions.. you can simply set your object's Debug property to true and the included functions will work the same. I'd just hate to see this break everyone's existing code upon a pull request. ( I WISH GO HAD OPTIONAL PARAMETERS!!!! >.< )

So we'd end up doing something like this instead

	// Connect to the BIG-IP system.
	f5 := bigip.NewSession("ltm.company.com", "admin", "secret", nil)

        // Turn on Debug
        f5.Debug = true

 	// Get a list of all VLAN's, and print their names to the console.
	vlans, err := f5.Vlans()
 	if err != nil {
 		fmt.Println(err)
 	}