[GiNaC-devel] Fixed problem on 64-bit machines and introduced has_options::algebraic.

Dear all, I found out that the new tinfo() system does not compile on AMD 64-bit machines because integers are still 32 bit on them. This makes the cast from void* to unsigned illegal. I solved this problem. I also introduced an extra optional argument for .has() that can be used to pass a has_option. I defined has_options::algebraic. This is analogous to subs_options::algebraic. For example (x*y*z).has(x*y,has_options::algebraic) will return true. I also included some checks for correct behavior of this feature in the check directory and documented it in the tutorial. Best, Chris