csrgen: Use data_sources option to define which fields are rendered
    
    This removes the ipa.syntaxrule and ipa.datarule macros in favor of
    simple 'if' statements based on the data referenced in the rules. The
    'if' statement for a syntax rule is generated based on the data rules it
    contains.
    
    The Subject DN should not be generated unless all data rules are in
    place, so the ability to override the logical operator that combines
    data_sources (from 'or' to 'and') is added.
    
    https://fedorahosted.org/freeipa/ticket/4899
    
    Reviewed-By: Jan Cholasta <jcholast@redhat.com>