vim: Remove bundle submodules

Signed-off-by: John Else <john.else@citrix.com>
vim: Remove pathogen

Signed-off-by: John Else <john.else@citrix.com>
vim: Add NeoBundle

Signed-off-by: John Else <john.else@citrix.com>
Update .gitignore

Ignore all bundles, apart from NeoBundle itself.

Signed-off-by: John Else <john.else@citrix.com>