added properties after, first
set list of columns to final
created class AddColumnConfig to hold the position the column should be
added
added add before column
CORE-929 Support for ordering of columns in addColumn

Merged in pull request https://github.com/liquibase/liquibase/pull/89 that adds beforeColumn, afterColumn and position attributes to <column>
CORE-929 Support for ordering of columns in addColumn

Merged in pull request https://github.com/liquibase/liquibase/pull/89 that adds beforeColumn, afterColumn and position attributes to <column>