fix screen to run on terminals with long $TERM

According to tic man page:
Terminal names exceeding the maximum alias length
(32 characters on systems with long filenames, 14 characters otherwise)
will be truncated to the maximum alias length and a warning message
will be printed.

Use 32 as it's bigger value and it won't matter on systems with smaller
filenames.

Signed-off-by: Amadeusz Sławiński <amade@asmblr.net>

src/display.h

@@ -73,7 +73,7 @@ struct display
   struct win *d_other;		/* pointer to other window */
   int   d_nonblock;		/* -1 don't block if obufmax reached */
 				/* >0: block after nonblock secs */
-  char  d_termname[20 + 1];	/* $TERM */
+  char  d_termname[32 + 1];	/* $TERM */
   char	*d_tentry;		/* buffer for tgetstr */
   char	d_tcinited;		/* termcap inited flag */
   int	d_width, d_height;	/* width/height of the screen */

src/screen.h

@@ -203,7 +203,7 @@ struct msg
 	  int nargs;
 	  char line[MAXPATHLEN];
 	  char dir[MAXPATHLEN];
-	  char screenterm[20];	/* is screen really "screen" ? */
+	  char screenterm[32];	/* is screen really "screen" ? */
 	}
       create;
       struct
@@ -215,7 +215,7 @@ struct msg
 	  char preselect[20];
 	  int esc;		/* his new escape character unless -1 */
 	  int meta_esc;		/* his new meta esc character unless -1 */
-	  char envterm[20 + 1];	/* terminal type */
+	  char envterm[32 + 1];	/* terminal type */
 	  int encoding;		/* encoding of display */
 	  int detachfirst;      /* whether to detach remote sessions first */
 	}