Please describe the problem:
Due (it seems) to DLL linking problems, on Cygwin, calls to __xmlRaiseError in
xmllint don't print the file and line numbers, instead printing only the message.

Steps to reproduce:
1. Install the Cygwin libxml2 package.
2. For the tests below, obtain and unpack the libxml2 source code.
3. xmllint -noout -schema libxml2-2.6.22/test/schemas/all_2.xsd
libxml2-2.6.22/test/schemas/all_2.xml 


Actual results:
Element 'c': This element is not expected.
libxml2-2.6.22/test/schemas/all_2.xml fails to validate

Expected results:
libxml2-2.6.22/test/schemas/all_2.xml:1: element c: Schemas validity error :
Element 'c': This element is not expected.
libxml2-2.6.22/test/schemas/all_2.xml fails to validate

Does this happen every time?
Yes.

Other information:
If xmllint is compiled statically, i.e. -static is passed to the libtool command
line when xmllint is compiled, the problem goes away.

The problem seems to occur because fprintf in a DLL has a different address than
fprintf in a main program, on Windows.