histedit: removing the experimental config 'histeditng' This config has been around for about 2 years now. So, it can be assumed to be stable. Therefore, I am removing the config. This also makes the test 'test-histedit-base.t' compatible with chg. Test Plan: - Ran the test 'test-histedit-base.t' with and without '--chg' option. - Ran all the other tests without '--chg' option. - Checked the output of 'hg help histedit'. Differential Revision: https://phab.mercurial-scm.org/D942

requesting all changes
adding changesets
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added 1 changesets with 4 changes to 4 files
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4 files updated, 0 files merged, 0 files removed, 0 files unresolved
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 4 changes to 4 files
updating to branch default
4 files updated, 0 files merged, 0 files removed, 0 files unresolved