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