shill: Add Technology class

Move Technology enum out into its own class, and create static
functions for converting between these and strings.

BUG=chromium-os:20114
TEST=Rerun unit tests

Change-Id: I9e3aea44e5d0b14d844328f023b01d7f8ea04c42
Reviewed-on: http://gerrit.chromium.org/gerrit/8204
Reviewed-by: Paul Stewart <pstew@chromium.org>
Tested-by: Paul Stewart <pstew@chromium.org>
diff --git a/wifi.h b/wifi.h
index a92174f..7687215 100644
--- a/wifi.h
+++ b/wifi.h
@@ -37,7 +37,7 @@
   virtual void Start();
   virtual void Stop();
   virtual void Scan(Error *error);
-  virtual bool TechnologyIs(const Technology type) const;
+  virtual bool TechnologyIs(const Technology::Identifier type) const;
   virtual void LinkEvent(unsigned int flags, unsigned int change);
 
   // called by SupplicantInterfaceProxy, in response to events from