Merge branch 'jd/userdiff-kotlin'

A new built-in userdiff driver for kotlin.

* jd/userdiff-kotlin:
  userdiff: add builtin diff driver for kotlin language.

userdiff.c

@@ -180,6 +180,18 @@ PATTERNS("java",
 	 "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?"
 	 "|[-+*/<>%&^|=!]="
 	 "|--|\\+\\+|<<=?|>>>?=?|&&|\\|\\|"),
+PATTERNS("kotlin",
+	 "^[ \t]*(([a-z]+[ \t]+)*(fun|class|interface)[ \t]+.*)$",
+	 /* -- */
+	 "[a-zA-Z_][a-zA-Z0-9_]*"
+	 /* hexadecimal and binary numbers */
+	 "|0[xXbB][0-9a-fA-F_]+[lLuU]*"
+	 /* integers and floats */
+	 "|[0-9][0-9_]*([.][0-9_]*)?([Ee][-+]?[0-9]+)?[fFlLuU]*"
+	 /* floating point numbers beginning with decimal point */
+	 "|[.][0-9][0-9_]*([Ee][-+]?[0-9]+)?[fFlLuU]?"
+	 /* unary and binary operators */
+	 "|[-+*/<>%&^|=!]==?|--|\\+\\+|<<=|>>=|&&|\\|\\||->|\\.\\*|!!|[?:.][.:]"),
 PATTERNS("markdown",
 	 "^ {0,3}#{1,6}[ \t].*",
 	 /* -- */