from cinap.  accept an xmlism.

Reference: /n/atom/patch/applied2013/htmlang
Date: Mon Aug  5 23:01:53 CES 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/libhtml/lex.c	Mon Aug  5 23:01:37 2013
+++ /sys/src/libhtml/lex.c	Mon Aug  5 23:01:39 2013
@@ -320,6 +320,7 @@
 	{L"amp", 38},
 	{L"and", 8743},
 	{L"ang", 8736},
+	{L"apos", 39},
 	{L"aring", 229},
 	{L"asymp", 8776},
 	{L"atilde", 227},