Correct some docs.
Add futures to requirements.txt.
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.