Added the ability to specify an environment in pake tasks. This is important for being able to create an index using a different environment's connection parameters. Usage remains the same, but you can now do something like this:
symfony lucene-rebuild myapp dev
... in order to build the index using the 'dev' environment. This is useful when you need to rebuild an index on your production server where your connection parameters are different for the 'dev' and 'prod' environments.
This is a backwards compatible change as you can leave off the environment and the pake task will work the same as before.
