revset: remove false condition to process 'negate' operator 'negate' is mapped to 'string' at the above clause.

revset: make optimize() reject unknown operators This should have caught the bug of 'keyvalue' operator fixed at 5004ef47f437. The catch-all pattern is useless since optimize() should be aware of all known operators.

help: show content for explicitly disabled extension (issue5228)

obsolete: fix minor module documentation issues

debugextensions: hide "ships-with-hg-core" magic string (BC) Since we have "bundled" flag, we no longer need to rephrase "ships-with-hg-core" to show as "internal".

debugextensions: show ships-with-hg-core state as a separate field This is less magical than rephrasing ships-with-hg-core as internal, and we can distinguish "internal" liar. "tested with: internal" will be hidden by the next patch.