evolve: prompt user to select destination for stabilization in case of split This patch adds functionality to prompt user to select a revision when there exists multiple stabilization destination because of split on multiple branches. Test are also added for the feature. I am not sure whether this is the best message which we can show, if people have suggestions I will like to improve the messages shown in prompt.

import hghave

@hghave.check("docgraph-ext", "Extension to generate graph from repository")
def docgraph():
    try:
        import hgext.docgraph
        hgext.docgraph.cmdtable # trigger import
    except ImportError:
        try:
            import hgext3rd.docgraph
            hgext3rd.docgraph.cmdtable # trigger import
        except ImportError:
            return False
    return True