Fix for secondary/shadow server duplicate ID issue

src/main/java/org/nrg/xnat/daos/HostInfoDAO.java

src/main/java/org/nrg/xnat/entities/HostInfo.java

src/main/java/org/nrg/xnat/initialization/RootConfig.java

...nat/services/impl/hibernate/HibernateHostInfoService.java

src/main/java/org/nrg/xnat/turbine/utils/IDGenerator.java