hqmf_r2.1: rename 'patientPopulation' to 'initialPopulation' in the generator.
hqmf_r2.1: remove 'contextControlCode' from author element in document template.
hqmf_2.1: escape text in value XML attribute in attribute template.
hqmf_r2.1: remove the 'type' from 'repeatNumber' in value template.
hqmf_r2.1: replace 'repeatNumber' with 'value' in the subset template, as 'repeatNumber' has wrong type.
hqmf_r2.1: escape more free-text strings in XML attribute values
hqmf_r2.1: In subset template, use 'repeatNumber' for 'COUNT' only, otherwise use 'value'