Add SmartVimStub method to pyVim.connect

The SmartVimStub method is an equivalent of the SmartConnect method.
The difference is that it returns a stub and it doesn't actually
try to login. It accepts all the arguments the SoapStubAdapter constructor
does.

pyVim/connect.py

@@ -34,6 +34,7 @@ import requests
 from requests.auth import HTTPBasicAuth
 
 from pyVmomi import vim, vmodl, SoapStubAdapter, SessionOrientedStub
+from pyVmomi.SoapAdapter import CONNECTION_POOL_IDLE_TIMEOUT_SEC
 from pyVmomi.VmomiSupport import nsMap, versionIdMap, versionMap, IsChildVersion
 from pyVmomi.VmomiSupport import GetServiceVersions
 
@@ -560,6 +561,49 @@ def __FindSupportedVersion(protocol, server, port, path, preferredApiVersions, s
          return desiredVersion
    return None
 
+def SmartStubAdapter(host='localhost', port=443, path='/sdk',
+                     url=None, sock=None, poolSize=5,
+                     certFile=None, certKeyFile=None,
+                     httpProxyHost=None, httpProxyPort=80, sslProxyPath=None,
+                     thumbprint=None, cacertsFile=None, preferredApiVersions=None,
+                     acceptCompressedResponses=True,
+                     connectionPoolTimeout=CONNECTION_POOL_IDLE_TIMEOUT_SEC,
+                     samlToken=None, sslContext=None):
+   """
+   Determine the most preferred API version supported by the specified server,
+   then create a soap stub adapter using that version
+
+   The parameters are the same as for pyVmomi.SoapStubAdapter except for
+   version which is renamed to prefferedApiVersions
+
+   @param preferredApiVersions: Acceptable API version(s) (e.g. vim.version.version3)
+                                If a list of versions is specified the versions should
+                                be ordered from most to least preferred.  If None is
+                                specified, the list of versions support by pyVmomi will
+                                be used.
+   @type  preferredApiVersions: string or string list
+   """
+   if preferredApiVersions is None:
+      preferredApiVersions = GetServiceVersions('vim25')
+
+   supportedVersion = __FindSupportedVersion('https' if port > 0 else 'http',
+                                             host,
+                                             port,
+                                             path,
+                                             preferredApiVersions,
+                                             sslContext)
+   if supportedVersion is None:
+      raise Exception("%s:%s is not a VIM server" % (host, port))
+
+   return SoapStubAdapter(host=host, port=port, path=path,
+                          url=url, sock=sock, poolSize=poolSize,
+                          certFile=certFile, certKeyFile=certKeyFile,
+                          httpProxyHost=httpProxyHost, httpProxyPort=httpProxyPort,
+                          sslProxyPath=sslProxyPath, thumbprint=thumbprint,
+                          cacertsFile=cacertsFile, version=supportedVersion,
+                          acceptCompressedResponses=acceptCompressedResponses,
+                          connectionPoolTimeout=connectionPoolTimeout,
+                          samlToken=samlToken, sslContext=sslContext)
 
 def SmartConnect(protocol='https', host='localhost', port=443, user='root', pwd='',
                  service="hostd", path="/sdk",