Log Message:
xmahjongg: force c++03. Fixes build issue (GCC 6.4)

permstr.cc: In function 'bool operator==(PermString, const char*)':
permstr.cc:163:26: error: no matching function for call to \ 
'operator==(PermString&, bool)'
   if (operator==(a, false) || !b)
                          ^
In file included from permstr.cc:19:0:
../include/lcdf/permstr.hh:113:1: note: candidate: bool operator==(PermString, \ 
PermString)
 operator==(PermString a, PermString b)
 ^~~~~~~~