update .gitattributes

.gitattributes

+# Autodetect text files
+* text=auto
+
+# ...Unless the name matches the following
+# overriding patterns
+
+# Definitively text files 
+*.txt text
+*.c text
+*.h text
+*.y text
+*.ac text
+*.m4 text
+
 *.dll binary
 *.exe binary
 *.a binary