Ignore cscope and vim swap files

This can perhaps be added to my global ignores instead, however since project .gitignore contained other similar items added it here.

$ git status
On branch master
Your branch is up-to-date with 'origin/master'.
nothing to commit, working directory clean
$ 
$ git status --ignored
On branch master
Your branch is up-to-date with 'origin/master'.
Ignored files:
  (use "git add -f <file>..." to include in what will be committed)

	.gitignore.swp
	libraries/cscope.in.out
	libraries/cscope.out
	libraries/cscope.po.out