don't let font set through -f leak into environment
of parent, and sundary cleanup.

Reference: /n/atom/patch/applied2013/vtcleanup
Date: Tue Jun 18 23:16:44 CES 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/vt/main.c	Tue Jun 18 23:16:07 2013
+++ /sys/src/cmd/vt/main.c	Tue Jun 18 23:16:07 2013
@@ -144,8 +144,9 @@
 	int i, blkbg;
 	char *p;
 
-	rfork(RFNAMEG|RFNOTEG);
+	rfork(RFENVG|RFNAMEG|RFNOTEG);
 
+	fontname = nil;
 	term = "vt100";
 	fk = vt100fk;
 	blkbg = nocolor = 0;
@@ -527,8 +528,7 @@
 				set_host(&e);
 				break;
 			default:
-				perror("protocol violation");
-				exits("protocol violation");
+				sysfatal("protocol violation: %r");
 			}
 		} while(newmouse == 1);
 		cursoff();	/* turn cursor back off */
--- /sys/src/cmd/vt/event.c	Tue Jun 18 23:16:07 2013
+++ /sys/src/cmd/vt/event.c	Tue Jun 18 23:16:07 2013
@@ -23,7 +23,7 @@
 static int
 start_host(void)
 {
-	int	fd;
+	int fd;
 
 	cs = consctl();
 
@@ -58,7 +58,7 @@
 	einit(Emouse|Ekeyboard);
 
 	outfd = start_host();
-	if( estart(Ehost, outfd, BUFSIZ) != Ehost) {
+	if(estart(Ehost, outfd, BUFSIZ) != Ehost) {
 		exits("event init error");
 	}
 }