of the plugin, move it to test/bootstrap

new package "sqlalchemy_nose" which installs
along with "sqlalchemy".  This so that the "nosetests"
script works as always but also allows the
--with-coverage option to turn on coverage before
SQLAlchemy modules are imported, allowing coverage
to work correctly.
- added some new ignores

correctly with the "mysqldb" dialect.  Previously,
the reconnect logic would fail for OperationalError
conditions, however since MySQLdb has its
own reconnect feature, there was no symptom
here unless one watched the logs.
[ticket:1848]

on_connect().  This method returns a callable which receives
the raw DBAPI connection after each one is created.   The callable
is assembled into a first_connect/connect pool listener by the
connection strategy if non-None.   Provides a simpler interface
for dialects.

and now supports SAVEPOINT operations.

on all new connections, which allows all String/Text/etc.
types to skip the need to post-process bytestrings into
unicode (an expensive step due to its volume).  Other
dialects which return unicode natively (pg8000, zxjdbc)
also skip unicode post-processing.

- String/Text/Unicode types now skip the unicode() check
on each result column value if the dialect has
detected the DBAPI as returning Python unicode objects
natively.  This check is issued on first connect
using "SELECT CAST 'some text' AS VARCHAR(10)" or
equivalent, then checking if the returned object
is a Python unicode.   This allows vast performance
increases for native-unicode DBAPIs, including
pysqlite/sqlite3, psycopg2, and pg8000.

See README.unittests for information on how to run
the tests.  [ticket:970]