[linux-cifs-client] fixed credentials file handling in mount.cifs

[Steve French]

I fixed the problem that Kieron pointed out with the credentials file
handling in the cifs mount helper mount.cifs (the password was including
the terminating new line character).  It is updated in the samba cvs and
a new prebuilt version (for x86) is available from the project page.

I also added a mnt_opts string when cifs adds mount entries to mtab so
the output of the mount command (with no parms, ie in order to display
mount information) that read that information from the file rather than
from the kernel (ie /proc/mounts) will include some information about
the mount flags for cifs mounts. 

Viewing the information in /proc/mounts had been ok since it invokes
kernel code to display that info, and is better since it includes more
detailed information although in a similar format.