Expand require_version and require_modules to support multiple releases

Currently, there is no way for modules to require dependent modules whose versions differ depending on the OpenMRS version they are installed into. To use a current example:

The reporting module requires OpenMRS 1.5. It also runs on OpenMRS 1.6.

The reporting module depends on serialization-xstream, which has 2 different branches, one that is compatible with OpenMRS 1.5 and one that is compatible with OpenMRS 1.6+.

As we upgrade the serialization-xstream module with bug fixes, we'll want to upgrade both lines independently. The 1.5 compatible version might be 0.1.8.2. The 1.6+ compatible version might be 0.2.4.

We'll want to represent this in our require_version / require_modules configuration. Something like the following:

<supported_versions>
  <supported_version range="[1.5,1.6)">
    <require_module id="org.openmrs.module.serialization.xstream" range="[0.1.8,0.2)" />
  </supported_version>
  <supported_version range="[1.6,*]">
    <require_module id="org.openmrs.module.serialization.xstream" range="[0.2,*]" />
  </supported_version>
</supported_versions>