Bugfixes in abstractapi.py and metadoc.py

* prevent metadoc.Translator.translate() from crashing when None
  is passed as argument.
* set the briefDescription attributes of enum values$

tools/abstractapi.py

@@ -593,6 +593,7 @@ class CParser(object):
 			valueName = EnumValueName()
 			valueName.from_camel_case(cEnumValue.name, namespace=name)
 			aEnumValue = EnumValue(valueName)
+			aEnumValue.briefDescription = cEnumValue.briefDoc
 			if cEnumValue.value is not None:
 				try:
 					aEnumValue.value_from_string(cEnumValue.value)

tools/metadoc.py

@@ -56,6 +56,9 @@ class Description:
 
 class Translator:
 	def translate(self, description):
+		if description is None:
+			return None
+		
 		lines = []
 		for para in description.paragraphs:
 			if para is not description.paragraphs[0]: