add getCompiler and getLinker methods, to abstract from XSD.
add calc_source_md5 as it's more convenient especially for embedded
targets to add -DPLC_MD5="something" option at compile time than
to mess with editing binary.
add some more helper methods

<?xml version='1.0' encoding='utf-8'?>
<BaseParams Name="HMI" IEC_Channel="0"/>