Added piconfx, an XSL Transformer accepting only an XSL file instead
of additionally XML files like xsltproc does, following the 'one
command, one file'-style of piconf. The XSL file, then of cource,
has to load the appropriate XML files as external entities or it
uses the XML nodes within itself. This enables PIML files expanding
themselves, becoming generic PIML files invoked like:
piconfx upgrade_all_devices.piml | piconfm
Corrected spelling.
piconfx now can read from stdin while still supporting standalone
XSL files applied against the dummy XML <piml/> using mkfifo with mktemp.

Though the prefered way seems to be to pass an XML file to piconfx
containing a <?xml-stylesheet ...?> processing instruction instead of using
standalone XSL files. If the processing instruction is missing, piconfx
just validates and dumps the XML file without transformation. xsltproc
itself would complain here with 'document is not a stylesheet'. But both,
plain XML and XML containing a stylesheet, are valid for piconfx.
Ugly but simple fix of piconfx. Had to replace cat with xmllint
in order to fetch remote files in case of plain XML. This causes
piconfx to always load plain XML files twice, which needs to be
avoided by a better patch.
Disabled remote connections for piconfx to fix previous problem
and to make sure no external resources are required for all times.
Replaced shell script piconfx with a more efficient C++ version
while providing more control like featuring URLs and remote resources,
again.
Finally removed shell version of piconfx.
The name of the one argument passed to the three binaries is now variable.
This is required since piconfx accepts an URL instead of a FILE only.
Make sure to not print partially parsed XML in case of an error.
Speeded up dump mode and fpath/xpath error handling by forking only
into the timer if necessary.

Moved manpages from doc/man to man in order to separate them from the
manual and the apiref which will be placed under doc.