* Get accurate reason when a query is not executed sucessfully. Disable test case for async query in lua51 connector.

* Add a build option to disable embedded lua lib. By default enable.

* Restore default dependency for module query to avoid compile error on windows.

This patch fixes a few error handling of memory allocation
failure while opening vnodes.

bonus fix: also add a new error code to indicate failure
of opening vnode. Before the patch, the function would simply
return -1 when vnode open fails.