fix: adapt to different locations for cdd includes

from master
Misc fixes due to building on Mac OS X 10.6

fix: no  pyobject-building if configured without dynamic loading
chg: minor include reordering + forward declarations + cosmetics
fix: AM_COND_IF may be undefined in older automake/autoconf
fix: distribute ALL tested tests
fix: no double definition of NATNUMBER/int_number in structs.h
fix: n_ExtGcd is not always related to HAVE_RINGS
update man page for Singular 4
initial Debian package support

* new folder debian

* added Debian files to EXTRA_DIST in Makefile.am

* added Singular desktop files as AC_CONFIG_FILES in configure.ac
Merge pull request #319 from mschulze/spielwiese

initial Debian package support
add: rudimentary Bertone/Cheze/Galligo absolute factorization

Conflicts:

	factory/GNUmakefile.in
chg: deleted debug output from absfact
chg: documentation
chg: renamed fac_absfact.* to facAbsFact.*
chg: changes to output and documentation
chg: added absolute irreducibility test
chg: added new templates to hold absolute factors

Conflicts:

	factory/canonicalform.h
	factory/ftmpl_inst.cc
chg: changes due to new template
chg: added more functions to templates
chg: added naive implementations of abs. irred. tests from
     Bertone, Cheze, Galligo
chg: top level abs factorization interface
chg: debug output and experimental code
chg: new command absBiFact
chg: convenient way to call absBiFact (i.e. handling of ring changes) via
     absBiFactorize
TODO: may be handle Gerhard's special output for absPrimDec
fix: univariate abs. factorization