fix building for lua

CMakeLists.txt

@@ -117,7 +117,7 @@ if (MacIntegration_FOUND)
 endif ()
 
 # Plugins / scripting
-pkg_check_modules (Lua "lua5.3")
+pkg_check_modules (Lua "lua >= 5.3")
 if (Lua_FOUND)
 	message("Enable Xournal++ Plugins")
 	add_includes_ldflags ("${Lua_LDFLAGS}" "${Lua_INCLUDE_DIRS}")

src/plugin/Plugin.cpp

@@ -5,10 +5,12 @@
 
 #ifdef ENABLE_PLUGINS
 
+extern "C" {
 #include <lua.h>
 #include <lauxlib.h>
 #include <lualib.h>
 #include <lauxlib.h>
+}
 
 #include "luapi_application.h"
 

src/plugin/Plugin.h

@@ -18,7 +18,9 @@
 #include <config-features.h>
 
 #ifdef ENABLE_PLUGINS
+extern "C" {
 #include <lua.h>
+}
 
 class Plugin;
 class Control;