Install manual of Lua interface

lua_install.patch

diff --git a/src/INSTALL b/src/INSTALL
--- a/src/INSTALL
+++ b/src/INSTALL
@@ -172,6 +172,30 @@
 And to not search for locally installed headers and libraries at all, use:
 	./configure --without-local-dir
 
+Unix: COMPILING WITH LUA
+
+When you want to compile with the Lua interface features enabled, make sure
+you compile on a machine where Lua is installed, otherwise the configure tests
+may fail.  You need to compile with "luainterp" features:
+	./configure --with-luainterp
+
+If Lua headers and libraries are installed not in /usr, for example in
+/usr/local, use:
+	./configure --with-luainterp --with-lua-prefix=/usr/local
+
+Or set LUA_PREFIX environment variable:
+	export LUA_PREFIX=/usr/local
+	./configure --with-luainterp
+
+When you want to compile with LuaJIT instead of Lua, make sure you compile on
+a machine where LuaJIT is installed, otherwise the configure tests may fail.
+You need to compile with --with-luajit in addition to --with-luainterp:
+	./configure --with-luainterp --with-luajit
+
+When you want to compile with Lua interface feature using dynamic loading,
+use:
+	./configure --with-luainterp=dynamic
+
 
 3. OS/2
 =======