Reworked main method to allow calling from other Java processes without exiting.
Added port to PostgreSQL connection string.
Corrections to SVG image work.
Default to showing images in case of Javascript problems.
Added Sybase JTDS driver.
Catch exception when trying to retrieve Sybase foreign keys.
See http://sourceforge.net/p/jtds/discussion/104389/thread/4fb41830/ for
possible fix.