build: lua module build fixes

- do not link with -llua. We should not link apk or lua module with it.
- default to lua 5.2
- allow override the lua version with LUA_VERSION
- allow override the lua pkg-config package with LUA_PC
- only add the pkg-config lua --cflags to the lua module

Makefile

@@ -15,9 +15,8 @@ LIBDIR		:= /lib
 CONFDIR		:= /etc/apk
 MANDIR		:= /usr/share/man
 DOCDIR		:= /usr/share/doc/apk
-LUA_LIBDIR	:= /usr/lib/lua/5.1
 
-export DESTDIR SBINDIR LIBDIR CONFDIR MANDIR DOCDIR LUA_LIBDIR
+export DESTDIR SBINDIR LIBDIR CONFDIR MANDIR DOCDIR
 
 ##
 # Top-level rules and targets

src/Makefile

@@ -4,11 +4,14 @@ LUAAPK ?= yes
 
 # lua module
 ifneq ($(LUAAPK),)
+LUA_VERSION		?= 5.2
+LUA_PC			?= lua$(LUA_VERSION)
+LUA_LIBDIR		?= /usr/lib/lua/$(LUA_VERSION)
 LIBAPK			:= YesPlease
-PKGDEPS			+= lua
 shlibs-y		+= apk.so
 apk.so-objs		:= lua-apk.o
-CFLAGS_lua-apk.o	:= -DAPK_VERSION=\"$(FULL_VERSION)\"
+CFLAGS_lua-apk.o	:= -DAPK_VERSION=\"$(FULL_VERSION)\" \
+			   $(shell $(PKG_CONFIG) $(LUA_PC) --cflags)
 LUA_LIB-y		:= $(obj)/apk.so
 install-LUA_LIB-y	:= $(INSTALLDIR) $(DESTDIR)$(LUA_LIBDIR) && \
 			   $(INSTALL) $(LUA_LIB-y) $(DESTDIR)$(LUA_LIBDIR)