Update preinstall so that submodule usage works for clean checkouts.
Update preinstall so that submodule usage works for clean checkouts.

maxogden/node-leveldb,maxogden/node-leveldb,maxogden/node-leveldb,my8bird/node-leveldb,my8bird/node-leveldb,mikepb/node-leveldb,my8bird/node-leveldb,mikepb/node-leveldb