Merge pull request #4921 from Leandros/master

Properly detect .h as a C++ header file

.gitattributes

@@ -1,3 +1,6 @@
+# Properly detect languages on Github
+*.h linguist-language=cpp
+
 *.cpp eol=lf
 *.h eol=lf
 *.py eol=lf