Determine to import unittest vs unittest2 in one place.
Remove all stress tests from test suite, since these are effectively tested in the other tests.
Keep one instance of 'test_stressed_rollback', but move it to test_rollbacks.py.
Remove useless test_shard_length tests.

Remove useless test_full_search tests.
Extract _search and _delete methods from mongo_doc_manager.py into MongoTestCase.
PEP-8 fixes for test suite.
Remove unused imports.
Remove unnecessary modifications to sys.path.
Extract _search and _remove methods from solr_doc_manager.py into SolrTestCase.
Give TestCase classes predictable names.
Consistently have sys.path[0:0] = [""] before importing local modules.
Use --smallfiles when starting test servers.
Log to STDOUT when running tests.