Added tables for Scrum-based projects, sprints, stories, tasks, etc.

Made minor adjustments to the Task table

Added 5 more task_status_type's and rearranged existing ones to better
support Scrum projects

Changed from ptt_schmea.sql to Rails-like timestamped sql file.  All
changes are going in timestamped sql files so that updates can be
applied without having to manually edit tables and data.  Still need to
manually run the sql files through mysql client program.  Future version
will be run through a Perl script that checkes the schema_migration
table and applies the appropriate updates.
incremented version; updated Changes