Adjust installation location to /usr.

Signed-off-by: Francois Perrad <francois.perrad@gadz.org>

Index: b/etc/lua.pc
===================================================================
--- a/etc/lua.pc
+++ b/etc/lua.pc
@@ -8,7 +8,7 @@
 R= 5.1.5
 
 # grep '^INSTALL_.*=' ../Makefile | sed 's/INSTALL_TOP/prefix/'
-prefix= /usr/local
+prefix= /usr
 INSTALL_BIN= ${prefix}/bin
 INSTALL_INC= ${prefix}/include
 INSTALL_LIB= ${prefix}/lib
Index: b/src/luaconf.h
===================================================================
--- a/src/luaconf.h
+++ b/src/luaconf.h
@@ -94,7 +94,7 @@
 	".\\?.dll;"  LUA_CDIR"?.dll;" LUA_CDIR"loadall.dll"
 
 #else
-#define LUA_ROOT	"/usr/local/"
+#define LUA_ROOT	"/usr/"
 #define LUA_LDIR	LUA_ROOT "share/lua/5.1/"
 #define LUA_CDIR	LUA_ROOT "lib/lua/5.1/"
 #define LUA_PATH_DEFAULT  \