update build.xml for DBSteward 1.2.4 release --

pgsql8 updates:
  - diff language create / drop bug
mysql5 updates:
  - preserve ENUM case during extraction
  - extract columns timestamp ON UPDATE configuration properly
General updates:
  - Quoting of some reserved words in pgsql8 and mysql5

Supported Platform DDL Generation and Differencing:
pgsql8    - PostgreSQL 8
mssql10   - Microsoft SQL Server 2008
mysql5    - MySQL 5

Supported Platform Structure Extraction into XML:
pgsql8    - PostgreSQL 8
mysql5    - MySQL 5