Set namespace on portType correctly (testcase: encapsecurity/authstateless.wsdl)
Fix crash in case of type not found.

Found while trying something, but then reverted that call. Still a bug.
Add missing fwd decls for the args used in server methods.

Found in the encapsecurity/authstateless.wsdl testcase, which gave
wsdl_authstateless.h:1505:82: error: ‘__ContextResponseType’ does not name a type
code formatting fix
Server code generation fix to avoid clashes

Rename request and response to _request and _response in order to avoid clashes
with variable names coming from the WSDL.

Testcase: encapsecurity/authstateless.wsdl
Fix infinite recursion when type A contains a member A with minoccurs=0

It needs to be stored as a QSharedPointer rather than as a value,
otherwise the constructor recurses infinitely.

So the code now has two reasons to use QSharedPointer: because the
type of polymorphic or because a class contains an optional instance of itself.

An indirect composition (A contains B contains A) wouldn't be detected, though...

Testcase: encapsecurity/authstateless.wsdl (class __StatusCodeType)
Add unittest from http://demo.encapsecurity.com/pt/encap-ws/auth/stateless?wsdl

(see the last 5 commits or so, for what this required fixing in kdsoap)