Add option to TFTP client to ignore ':' in file name

I have encountered a situation where I would like to use tftp-hpa to
retrieve a file that resides within an absolute path containing a ':'
character.  Ala, "tftp foobar -c get C:2/tftpdir/myfile".  Since the
tftp client automatically converts the host:file syntax, I get an
error "tftp: C: Unknown host".

I made a chage to the tftp client code to add a literal mode (-l),
that prevents the special treatment of the ':' character.  I've
attached a patch set for main.c and tftp.1.in for your consideration.
I'm not sure how many folks run into this, but it may be somewhat
common for VxWorks and perhaps MSDOS users.

Thanks,
Craig Johnston

tftp/tftp.1.in

@@ -60,6 +60,9 @@ command below.)
 Execute \fIcommand\fP as if it had been entered on the tftp prompt.
 Must be specified last on the command line.
 .TP
+.B \-l
+Default to literal mode. Used to avoid special processing of ':' in a file name.
+.TP
 \fB\-m\fP \fImode\fP
 Set the default transfer mode to \fImode\fP.  This is usually used with \-c.
 .TP
@@ -119,7 +122,12 @@ host, if the host has already been specified, or a string of the form
 .I "host:filename"
 to specify both a host and filename at the same time.  If the latter
 form is used, the last hostname specified becomes the default for
-future transfers.
+future transfers.  Enable
+.B literal
+mode to prevent special treatment of the ':' character (e.g. C:\\dir\\file).
+.TP
+.B literal
+Toggle literal mode.  When set, this mode prevents special treatment of ':' in filenames. 
 .TP
 \fBmode\fP \fItransfer-mode\fP
 Specify the mode for transfers;
@@ -151,7 +159,9 @@ form is used, the hostname specified becomes the default for future
 transfers.  If the remote-directory form is used, the remote host is
 assumed to be a UNIX system or another system using
 .B /
-as directory separator.
+as directory separator.  Enable
+.B literal
+mode to prevent special treatment of the ':' character (e.g. C:\\dir\\file).
 .TP
 .B quit
 Exit