Add basic vim config

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

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

Signed-off-by: John Else <john.else@citrix.com>
Add ocamlspot-helpers submodule

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

Signed-off-by: John Else <john.else@citrix.com>
Add ocaml-specific plugins

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