In general, a "design pattern" is a description or template for how to solve a problem that can be used to solve a variety of problems. On this site, and by popular usage, most people relate that term to semantic constructs and templates used to solve a variety of programming challenges. As already pointed out by P.Brian.Mackey, the term was popularized by the Gang of Four to categorize the common programming strategy and patterns they have observed and recorded. However, the design pattern concept applies to strategies in architectural challenges in construction or manufacturing as well. Really, any type of domain problems can have design patterns applied to them as part of the process for creating widgets used, in part or in whole, to come to a final solution.
So, I can understand your confusion about the function of a stack and CVS as representing a design pattern, of storing and retrieving, state information. However those are not a pattern for solving a problem, they are widgets, or a finished product that helps solves some kind of problem domain.
A stack is a data structure, or abstractly speaking a tool or widget. It is not a design pattern. However, it is a representation of the OO design pattern, associating data and its function together providing a limited interface abstracting details from the things which use it. A stack could also be said to be a tool that implements the Last in First Out (LIFO) storage design pattern.
CVS and Git are not really the function of a design pattern, they are applications. What you are describing in relation to popping and pushing data, although inaccurate, is part of the workflow of those applications. In CVS and git you fetch data from a certain point of its lifetime, modify it, and then tell the CVS or Git to save those changes so you, or someone else, can fetch those changes. I just trivialized the basics of those systems, but their underlying differences are how they store information and how people access and work with the data. See http://stackoverflow.com/questions/802573/difference-between-git-and-cvs if you would like to get more detail on their differences.