* this seriously improves startup improvement for gbuild
   (for example from 9.3s to 5.2s for an noop offapi build)

- Adapted linkoo's link_gdb_py to libs moved from basis to brand layer.
- Fixed install-gdb-printers's handling of Mac OS X ".dylib" suffix.
- No need to call install-gdb-printers from top-level make dev-install;
  linkoo's link_gdb_py already does that.

adapt sc unittests to separate RdbTarget makefile requirement, also rename sc_test_filters consistent to sc_filters_test

Move the struct OSQLParser_Data definition to the sqlparse.hxx
header. A somewhat ugly workaround for warning C4150: deletion of
pointer to incomplete type 'connectivity::OSQLParser_Data'; no
destructor called.