small bug in more

[morgan at UCI-750A.ARPA]

From:  Tim Morgan <morgan at UCI-750A.ARPA>

Description:
	In more, the routine initterm() is called to initialize the
	terminal capabilities which are used subsequently.  It uses
	a buffer called "clearbuf" of 100 bytes to store the capability
	strings into, using the termcap(3) routines (eg, tgetstr(3)).
	But since clearbuf is local to initterm(), when that routine
	exits, clearbuf and the pointers to the capability strings stored
	within it can be overwritten by other routines.

	Normally more works because just before clearbuf is another
	array called "buf" which is 1024 bytes long.  Thus clearbuf is
	high enough (or low enough, depending on how you look at it)
	on the stack that it avoids being trashed.
Repeat-By:
	Modify more so that some routine uses (writes on) more than 1024 bytes
	of space on the stack.  More will no longer correctly do things
	like clear the screen or change to or from inverse video.
Fix:
	Change the declaration of "clearbuf" in initterm() from

		char clearbuf[100];
	to
		static char clearbuf[100];