Ignore multiple vim swapfiles

In case there is more than one swapfile for a file (.swo, .swn, ...)
Merge branch 'master' of https://github.com/github/gitignore
Remove patterns covered by other templates

Remove redundant patterns, and patterns for generic backups, version
control dirs, IDEs, OSX.
Covered by global vim template
Merge pull request #839 from jean/master

Clean up the plone template