Arrange to always load trilite before importing sqlite.

This should let me get Flask going on our ancient production RHEL 5.5 box, which has trilite built against a version of sqlite that isn't the system one. I can't build a new one because this version of RHEL doesn't have the necessary header (sqlite3ext.h).

Also, merge the 2 redundant trilite loaders, and just load trilite at import time.