[pymvpa] further LIBSVM wrapper optimizations

[Valentin Haenel]

Hi,

last friday we refactored the LIBSVM interface further. This time we made
some modifications to the 

    mvpa/clfs/libsvmc/svmc.i

to move a loop from python to C.

This is obviously a very intrusive modification, if we made a mistake the code
may segfault (which should never happen). Therefore i put it in a separate branch 
val/libsvm-wrapper on alioth, so that the code can be reviewed. 

In my case this took my total time down from 1:48 to 1:08 so thats quite a bit.
Though i have no idea how this scales with input.

unittests are running :)

V-