#17 bbmail doesn't build with gcc 4.3 and glibc 2.8

[Santiago M. Mola]

gcc 4.3 and glibc 2.8 are much stricter with headers than previous versions.

In order to build bbmail-0.9.3 with them, #include <string.h> (or the standard <cstring>) should be added to baseresource.cpp, bbmail.cpp, main.cpp and resource.cpp.</cstring></string.h>

The exact headers available for C and C++ are listed in http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt01ch03s02.html

I'm attaching a patch with the required changes, and in the process I also converted the old headers to the C++98 standard ones.

[Santiago M. Mola]