cmake: bring back for good It's just too complicated to get portability done right using pure GNU make and since we're targeting more OSes than Linux we have to incorporate some portability bits.

# CMake files.
^build

# vim/emacs specific.
^tags$
^tags\.lock$
^tags\.temp$
^cscope\.out$
\.swp$
\.swo$

# macOS specific.
\.DS_Store$