Some build tests

Hi,

With Debian planning to switch to GCC 4.2 by default soon, I tried to
build the latest Amaya release with it. One of the changes with it is
that assigning a constant string to a 'char*' generates a warning, and a
'const char*' to a 'char*' an error.

Building Amaya generates about 7000 of this new warning, so I tried to
get rid of a few of them. The attached patches, when applied in order
reduce the number of warnings to 3080, which is a good start, just by
declaring a certain number of 'const char *' instead of 'char *'.

Also, you might be interested to know that I tried to build using the
latest version of wxWidgets, and that as far as my tests went, the build
was successful and amaya could start correctly. Also, I'm not sure
whether it's related or not, but I could run it with the DRI disabled,
so the long-standing crashing bug might be gone.

As usual, any question, please don't hesitate to ask.

Thanks,
Regis