DTD Config files pre version 1.5 lack tests and verification

After my team created the DTD file for version 1.6 and fixed the config DTD file for version 1.5. We noticed that the other DTD files that were part of the daily builds on https://ci.openmrs.org/browse/DOC-DOC/ are all without proper tests and as such lack verification.  This could potentially result in config DTD files that contain syntax errors and other issues that are going unnoticed by the system. We as a team propose that tests should be created for each past config file so that this problem can be solved. The tests are written in Java and could be written under a file name such as ModuleConfigFileDTDTest.java and put under the dtd file. For further reference, tests have already for the 1.6 DTD and can be found here in the comments: https://issues.openmrs.org/browse/TRUNK-5403