Fix build with GLIBC-2.12

http://bugs.gentoo.org/show_bug.cgi?id=333843

--- src/Makefile.am
+++ src/Makefile.am
@@ -82,8 +82,8 @@
 painter.h  \
 ticket.c  \
 ticket.h \
-endian.c \
-endian.h \
+bo_endian.c \
+bo_endian.h \
 version.c \
 version.h
 
--- src/hosbackingfile.c
+++ src/hosbackingfile.c
@@ -18,6 +18,7 @@
  */
 
 #include "hosbackingfile.h"
+#include "bo_endian.h"
 
 #define DEFAULT_BUF_SIZE 512
 
--- src/nih.c
+++ src/nih.c
@@ -24,7 +24,7 @@
 #include "hosdimensionblock.h"
 #include "hosbackingblock.h"
 #include "hosbackingfile.h"
-#include "endian.h"
+#include "bo_endian.h"
 
 /*  --- header contents ----
  *