DCMparagraph id attribute should be optional

[kohlhase]

We get an error when we do not specify an id key on \DCMparagraph (and I suspect on \DCM*section as well, the code looks similar).

Fatal:perl:die Can't call method "getValue" on an undefined value at /Users/kohlhase/stc/stex/sty/dcm/dcm.sty.ltxml line 131.
In Constructor[\DCMparagraph OptionalKey... defined /Users/kohlhase/stc/stex/sty/dcm/dcm.sty.ltxml line 136
 <= Whatsit[\DCMparagraph,undef,List[Box[... <= List[Box[␍],Comment[%\maketitle{}],Co... <= Constructor[\begin{document} Optional... <= ...
lastenheft.tex#textrange(from=826;0,to=826;118) at /opt/local/lib/perl5/site_perl/5.8.9/LaTeXML/Global.pm line 207.

But the id key should be optional, which means we should generate an xml:id if we do not find an id key.

BTW, it seems to me that the \DCM*section can be refactored.

[kohlhase]

Ran into this error again, that one probably also exists on the other DCM sectioning commands.

[deyan]

This was a dumb bootstrapping issue that I had looked over before, sorry.

Should be fixed now.