* os9kread.c (record_minmal_symbol): add section_offset to
relocate minimal symbol table.
* os9kread.c (read_minimal_symbols): ditto.
* os9kread.c (os9k_symfile_init): increase size of dbg and stb
file names.
* os9kread.c (read_os9k_psymtab): if there's no dbg file, just
return. Also if file addr is 0 leave it 0, not to relocate.
* remote-os9k.c (_initialize_remote_os9k): add 'set remotexon',
'set remotexoff' and 'set remotelog' commands.