upas/marshal: encode UTF8 in subject lines
 [rsc] --rw-rw-r-- M 128579 glenda sys 33818 Mar 31 12:48 sys/src/cmd/upas/marshal/marshal.c
	[diffs elided - too long]
	[diff -c /n/sourcesdump/2006/0331/plan9/sys/src/cmd/upas/marshal/marshal.c /n/sourcesdump/2006/0401/plan9/sys/src/cmd/upas/marshal/marshal.c]
 [rsc] --rw-rw-r-- M 128579 glenda sys 4272 Mar 31 17:59 sys/src/cmd/upas/fs/dat.h
	/n/sourcesdump/2006/0331/plan9/sys/src/cmd/upas/fs/dat.h:134,140 - 
	/n/sourcesdump/2006/0401/plan9/sys/src/cmd/upas/fs/dat.h:134,140
	  int		cistrcmp(char*, char*);
	  int		latin1toutf(char*, char*, char*);
	  int		windows1257toutf(char*, char*, char*);
	- int		decquoted(char*, char*, char*);
	+ int		decquoted(char*, char*, char*, int);
	  int		xtoutf(char*, char**, char*, char*);
	  void		countlines(Message*);
	  int		headerlen(Message*);
 [rsc] --rw-rw-r-- M 128579 glenda sys 27463 Mar 31 17:59 sys/src/cmd/upas/fs/fs.c
	/n/sourcesdump/2006/0331/plan9/sys/src/cmd/upas/fs/fs.c:1403,1409 - 
	/n/sourcesdump/2006/0401/plan9/sys/src/cmd/upas/fs/fs.c:1403,1409
	  		decoded[len] = 0;
	  	} else if(cistrncmp(token, "q?", 2) == 0){
	  		token += 2;
	- 		len = decquoted(decoded, token, e);
	+ 		len = decquoted(decoded, token, e, 1);
	  		if(len > 0 && decoded[len-1] == '\n')
	  			len--;
	  		decoded[len] = 0;
 [rsc] --rw-rw-r-- M 128579 glenda sys 29022 Mar 31 17:59 sys/src/cmd/upas/fs/mbox.c
	/n/sourcesdump/2006/0331/plan9/sys/src/cmd/upas/fs/mbox.c:1042,1048 - 
	/n/sourcesdump/2006/0401/plan9/sys/src/cmd/upas/fs/mbox.c:1042,1048
	  	case Equoted:
	  		len = m->bend - m->body;
	  		x = emalloc(len+2);	// room for null and possible extra nl
	- 		len = decquoted(x, m->body, m->bend);
	+ 		len = decquoted(x, m->body, m->bend, 0);
	  		if(m->ballocd)
	  			free(m->body);
	  		m->body = x;
	/n/sourcesdump/2006/0331/plan9/sys/src/cmd/upas/fs/mbox.c:1189,1195 - 
	/n/sourcesdump/2006/0401/plan9/sys/src/cmd/upas/fs/mbox.c:1189,1195
	  }
	  
	  static char*
	- decquotedline(char *out, char *in, char *e)
	+ decquotedline(char *out, char *in, char *e, int uscores)
	  {
	  	int c, soft;
	  
	/n/sourcesdump/2006/0331/plan9/sys/src/cmd/upas/fs/mbox.c:1208,1213 - 
	/n/sourcesdump/2006/0401/plan9/sys/src/cmd/upas/fs/mbox.c:1208,1215
	  		c = (*in++) & 0xff;
	  		switch(tableqp[c]){
	  		case Self:
	+ 			if(uscores && c == '_')
	+ 				c = ' ';
	  			*out++ = c;
	  			break;
	  		case Hex:
	/n/sourcesdump/2006/0331/plan9/sys/src/cmd/upas/fs/mbox.c:1225,1231 - 
	/n/sourcesdump/2006/0401/plan9/sys/src/cmd/upas/fs/mbox.c:1227,1233
	  }
	  
	  int
	- decquoted(char *out, char *in, char *e)
	+ decquoted(char *out, char *in, char *e, int uscores)
	  {
	  	char *p, *nl;
	  
	/n/sourcesdump/2006/0331/plan9/sys/src/cmd/upas/fs/mbox.c:1234,1244 - 
	/n/sourcesdump/2006/0401/plan9/sys/src/cmd/upas/fs/mbox.c:1236,1246
	  
	  	p = out;
	  	while((nl = strchr(in, '\n')) != nil && nl < e){
	- 		p = decquotedline(p, in, nl);
	+ 		p = decquotedline(p, in, nl, uscores);
	  		in = nl + 1;
	  	}
	  	if(in < e)
	- 		p = decquotedline(p, in, e-1);
	+ 		p = decquotedline(p, in, e-1, uscores);
	  
	  	// make sure we end with a new line
	  	if(*(p-1) != '\n'){