Warning level reduced from double -A to single -A

2) Disable SGI remark: controlling expression is constant

  Due to the HP-UX socklen_t issue it is insane to use the +w1 warning level.
  It generates more than 1100 warnings on socklen_t related statements.

  Until the issue is somehow fixed we will just use the +w2 warning level.

  Disallow run-time dereferencing of null pointers.

  Disable some remarks:

    #4227: padding struct with n bytes to align member.

    #4255: padding size of struct with n bytes to alignment boundary.

option to specify dis(activation) of compiler optimizations.

If option is specified, it will be honored independant of the
--(dis|en)able-debug option.

option to specify dis(activation) of picky compiler warnings.

If option is specified, it will be honored independant of the
--(dis|en)able-debug option.

If option is not specified, it will follow --(dis|en)able-debug
setting, whose default is disabled if not specified.