In case of defining paths in config, which wrapper is trying to
normalize, sometimes it may happen, that paths can be either local or
remote - depending on the intention, i.e. one can add:
cdrom_drive_0: foo.iso
where foo can be either an unpacked file or just some companion image,
which exists within config file.
In this patch calculated path is checked against file existence, and if
it doesn't exists, original value is preserved.
To give user a possibility to choose what archiver he can use another
options was introduced for cd32 and archive wrapper modules. This option
will indicate what archiver should be used for compressing the save
state directories.
Also, new command was added to utils - run_command which is an
generalized subprocess.call function.
Requirements is now added with module six, which was needed to detect
string-like objects in sane way.
Added safe guards for get_config function, introduced CmdOption class
for convenient accessing options as a dict keys with option to make them
as a list of commandline options suitable for passing to fs-uae.
