XML SAX parsing:
	XML::SAX::Expat:
		Tested XTM::XML parser with XML::SAX::Expat (0.30). It works but segfaults
		at program termination, so it passes the tests.
	XML::LibXML::SAX:
		If you are using XML::LibXML::SAX use versions >= 1.40. Earlier version did not
		like to have a "die" during the parse process. The currently latest version (1.49)
		depends on gdome libraries which are not Debianized yet. I'm not sooo desperate...
	XML::SAX::PurePerl:
		It is slow but it works.

XTM Syntax:
	xml:base is not yet honored (have to figure out what it does)

AsTMa parsing speed:
	The current parser (Parse::RecDescent) is powerful but slow. I will write my
	own.

xtm.pl: 
	If a (AsTMa or XTM) topic map has changed in the file system, a "load" will still
	use the old version (cached in XTM::Virtual)

astma2xtm.pl:
	VERSIONs do not show up correctly
	may not work with more recent versions of AsTMa= (including reification)