SQLite Adapter Updates

[<rfbaumann@gmail.com>]

Because SQLite only supports a limited subset of the ALTER TABLE
syntax [1], a number of SQLite adapter methods would fail due to their
use of it [2]. I've made a fork on GitHub which should have fixes for
many of these, brought in from mainline ActiveRecord:
http://github.com/ryanfb/activerecord-jdbc-adapter. This should fix
rename_column, change_column, and change_column_default, improve
remove_column, and alias in remove_columns. With these changes many
more projects should be able to be successfully DB migrated under
JRuby with SQLite for development/testing.

[1] http://www.sqlite.org/lang_altertable.html
[2] http://kenai.com/jira/browse/ACTIVERECORD_JDBC-16

Thanks,
-Ryan