clonebundle: update hook arguments (BC) By calling applybundle() with 'clonebundles' and the url instead of calling processbundle(), the hooks will get different arguments: HG_SOURCE will be 'clonebundles' instead of 'bundle2' and HG_URL will be the url instead of 'bundle2'. This is consistent with the bundle1 behavior and seems like a bug fix, but I'm marking it BC anyway.

commands: move checkconflict to bookmarks module Again, commands.bookmark is getting too large. checkconflict already has a lot of state and putting it in the bmstore makes more sense than having it as a closure. This also allows extensions a place to override this behavior. While we're here, add a documentation string because, well, we should be documenting more of our methods.

commands: move checkformat to bookmarks module commands.bookmark has grown quite large with two closures already. Let's split this up (and in the process allow extensions to override the default behavior).