Microposts, initial modeling

This includes microposts, migration, and initial associations with
users.
Micropost ordering is now correct.
microposts now delete with user.

Also removed a series of tests that have never passed and just annoyed
the heck out of me for whatever reason.  I don't really care.
Micropost data checking.
Users page shows microposts.
Sample posts for some users.
Microposts now can post from pages.
Micropost creation and deletion.