Retire #ifdef SYZYGY macro

It just clutters the code for no
real reason.

No functional change.

Resolves #139
Rewrite TBScore in uci_pv()

Streamline the code and make
it understandable.

No functional change.

Resolves #135
Cleaning Syzygy profiling data

Updating the makefile so that the clean and gcc-profile-clean targets also
remove the profiling data files in the syzygy directory.

No functional change.

Resolves #136
Remove CONNECTED_KINGS from Syzygy code

No functional change

Resolves #140