FreeBSD port

[Alex Samorukov]

Hi

I was able to compile sources on FreeBSD. 1 change was related to cmake, 
and 2 other - to malloc. To compile it I used dlmalloc() port, because 
with freebsd 7 malloc() i`m getting unreferenced symbol 
malloc_usable_size when i`m using c++.

So it was linked fine, but when i`m trying to test it on images from 
tarball, i`m getting segfault. The same problem is on my Ubuntu amd64 
box, so i`m not sure that bug is in BSD.

Ubuntu uses gcc 4.2.3, and FreeBSD 7 - gcc 4.2.1.