Recommended version of SWIG for building mapscript

[Umberto Nicoletti]

Devs,
do we have a recommended swig version?

I am still using 1.3.21 but that seems not to be what is used to build MS4W.
Versions of swig greater than 1.3.24 break the java tests because of a
new way of handling enumerations. There is a quick fix for Java that
makes newer swig handle enumerations like in 1.3.21, but I fear this
will break apps of existing MS4W users.

Maybe we should decide to adopt a common version on swig to avoid
these kind of issues in the future?

Umberto