doc for /precompiled/stack added

Rev: doc/precompiled/stack:1.1

doc/precompiled/stack

+NAME
+	/precompiled/stack - generic stack
+
+DESCRIPTION
+	/precompiled/stack is a Pike program that implements a generic stack.
+	The stack can hold any amount of values.
+
+	Only three methods are available: push(), pop() and reset()
+
+============================================================================
+NAME
+	push - push a value on the stack
+
+SYNTAX
+	#include <stack.h>
+
+	void stack->push(mixed value)
+
+DESCRIPTION
+	This function pushes a value on top of the stack. There is always
+	room for more values on the stack. (Until you run out of memory.)
+
+============================================================================
+NAME
+	pop - pop a value off the stack
+
+SYNTAX
+	#include <stack.h>
+
+	mixed stack->pop()
+
+DESCRIPTION
+	This function pops the topmost value off the stack. If there are
+	no values left on the stack a 'stack underflow' error is generated.
+
+============================================================================
+NAME
+	reset - remove all values from the stack
+
+SYNTAX
+	#include <stack.h>
+
+	void stack->reset()
+
+DESCRIPTION
+	This function simply returns the stack to it's original state: empty.
+
+============================================================================