[xmlsec] Link error (_xmlSecNodeSignature, _xmlSecDSigNs)

[Aleksey Sanin]

These are not functions but strings from the libxmlsec.lib.
However, you have to be very careful with importing/exporting any
data structures from Windows dlls. The example makefiles in the
xmlsec package have all the flags set correctly. You should
probably take a look and make sure that your project files
settings match these makefiles.

Aleksey