save point in migration to postgres.  postgres_sqlalchemy_move.py is main migration script.

collection.py and item.py currently have a mix of old and new code, and so are very messy
unittests all passing.
remove safeguard that postgres be on localhost
add JSONEncodedObj from https://gist.github.com/dbarnett/1730610.  thank you @dbarnett!
fix import source for new objects
create a collection_tiid object and table

also created an AddedItems table but that hasn't been tested yet
add tests for added_items object
create rows in collection_tiid and added_item tables while running through collections during migration
set drop_all to false
migration scripts use command line arguments like real grownup programs

helps running on staging
add doublecheck so we don't drop tables or run against the production database by accident
more robust job of restarting migration where it left off.

also add argument support of variable couch pagesize
move collection and item migration functions from script to main codebase so we can use them from app

item.py and collection.py are now, temporarily, even messier than they were.
but code reuse ftw, and will continue refactoring to clean.
handle starting at an arbitrary startkey
save point
Merge branch 'remove-non-v1' into postgres

Conflicts:
	test/unit_tests/test_views.py
run migration script using multiple threads.  change structure of alias table to include tiid.
try to fix memory leak using limit(1)
add some more limit(1)s
config number of threads
print timestamp