scmutil: changed revrange code not to use append Removed one call to the append method

push: provide a hint when no paths in configured (issue3692) When user type "hg push" command then this patch helps user by providing hint if no default path is configured. Second patch is the test coverage, to test the change behaviour of first patch.

revlog: introduce commonancestors method for getting all common ancestor heads

localrepo: commit: avoid calling expensive ancestor function when p1 is nullrev

ancestors: remove unnecessary handling of 'left' If one of the initial nodes also is an ancestor then that most be the only ancestor. There is no need for additional bookkeeping.

parsers: remove unreachable and invalid code in index_ancestors The function normally returns a list. Returning a single element instead of a list with one element would be weird.

cmdutil: implemented new lazy increasingwindows Now log can work in a lazy way and get results as soon as they are processed. Performance Benchmarking: $ time hg log -l1 -qr "branch(default)" 0:9117c6561b0b real 0m2.303s user 0m2.252s sys 0m0.048s $ time ./hg log -l1 -qr "branch(default)" 0:9117c6561b0b real 0m0.238s user 0m0.199s sys 0m0.037s