ENH: Cleanup Find* modules with new HINTS feature

- The find_* commands now provide a HINTS option.
  - The option specifies paths to be preferred over the system paths.
  - Many Find* modules were using two find calls with NO_DEFAULT_PATH
    to approximate the behavior, but that blocked users from overriding
    things with CMAKE_PREFIX_PATH.
  - This commit uses the HINTS feature to get desired behavior in
    only one find command call.

Modules/FindXMLRPC.cmake

@@ -101,10 +101,8 @@ IF(XMLRPC_FOUND)
       # Look for this library.
       FIND_LIBRARY(XMLRPC_${name}_LIBRARY
         NAMES ${name}
-        PATHS ${XMLRPC_LIBRARY_DIRS}
-        NO_DEFAULT_PATH
+        HINTS ${XMLRPC_LIBRARY_DIRS}
         )
-      FIND_LIBRARY(XMLRPC_${name}_LIBRARY NAMES ${name})
       MARK_AS_ADVANCED(XMLRPC_${name}_LIBRARY)
 
       # If any library is not found then the whole package is not found.