TRUNK-5399 Add and fix config xml dtd files 1-0.1.5

[teleivo]

Description of what I changed

• add the DTD files for the config.xml in versions 1.0-1.5 to the
  resources of org/openmrs/module/dtd so they are under version control,
  can easily be found, edited and uploaded back to resource.openmrs.org
• add elements that were not declared and thus made the DTDs invalid and
  not useful for devs writing their config.xml

dwr

• add missing elements judging from legacyui dwr element in config.xml
• create (param, include*) always has a param and can have 0-N include's
  param and include are empty elements with required attributes
• convert has one optional param child

mappingFiles

• fix the mappingFiles quantifier since it should only occur Zero or One
  time thus use ?. mappingFiles itself can have multiple whitespace
  separated filenames

require_modules

• be more strict on require_modules which should have 1-N require_module
  instead of 0-N, because why declare it if you dont require any module

aware_of_modules

• add aware_of_modules element to version 1.4, which was missing in
  the file uploaded to resources.openmrs.org and this also has to have 1-N
  aware_of_module if added

filter-mapping

• filter-mapping added in 1.2 defines that one of the following
  url-pattern or servlet-name elements must be included thus the pattern
  (url-pattern | servlet-name)

Issue I worked on

see https://issues.openmrs.org/browse/TRUNK-5399

[coveralls]

Coverage increased (+0.003%) to 59.012% when pulling 2bf2372 on teleivo:TRUNK-5399 into b800f2d on openmrs:master.