Provide support for D and VALA language files

This change adds file extension detection support for .d and .vala
files, which are used by the D and VALA programming languages,
respectively.

Closes:	#258
Signed-off-by: Enji Cooper <[email protected]>

Author: ngie-eign

identify/extensions.py

@@ -55,6 +55,7 @@
     'cxx': {'text', 'c++'},
     'cxxm': {'text', 'c++'},
     'cylc': {'text', 'cylc'},
+    'd': {'text', 'd'},
     'dart': {'text', 'dart'},
     'dbc': {'text', 'dbc'},
     'def': {'text', 'def'},
@@ -309,6 +310,7 @@
     'xsd': {'text', 'xml', 'xsd'},
     'xsl': {'text', 'xml', 'xsl'},
     'xslt': {'text', 'xml', 'xsl'},
+    'vala': {'text', 'vala'},
     'yaml': {'text', 'yaml'},
     'yamlld': {'text', 'yaml', 'yamlld'},
     'yang': {'text', 'yang'},