Add detailed tomcat instructions to INSTALL.md.
Add detailed tomcat instructions to INSTALL.md.

Make note at the top of the file about working code living on the
demo-client branch, and add a lot of specific set up information for
Debian users.

PCNI/OpenHMIS,PCNI/OpenHMIS,PCNI/OpenHMIS,PCNI/OpenHMIS,OpenTechStrategies/OpenHMIS