test-keyword: remove remaining sed calls

keyword: disable expansion in kwfilelog.read() if file renamed in node Simplifies kwfilelog.cmp() and avoids fiddling with/importing revlog. Reorder imports alphabetically.

keyword: make iskwfile() a weeding method in lieu of a boolean Update iskwfile docstring.

keyword: support copy and rename copy/rename destinations being unversioned and possibly ignored by the extension should not contain expanded keywords. Files copied/renamed from an ignored source are not touched. Add tests covering both of the above cases, plus the corner case of cp symlink foo; hg cp -A symlink foo (where foo becomes a regular file).

keyword: refactor kwtemplater.overwrite() Make kwexpand, kwshrink restricted commands - i.e. read from filelog without expansion for substition in kwtemplater.overwrite, and set/unset restricted mode for overwrite() in in kwcommitctx and the dorecord wrapper. Preselect candidates when working on changed files (rollback, record) outside kwtemplater class, and remove 6th argument from overwrite(). Avoid duplicate substitution/search in overwrite(): Only go into restricted read mode when reading from filelog. rollback and record read from the working directory, where restricted mode would already shrink keywords before overwrite() either expands or shrinks them again. This ensures that the usual automatic operations on keywords are turned off during overwrite() and only overwrite() itself acts on them. Reduce manifest calculation to the cases where it is needed. Move helper function for expansion removal outside kwtemplater class.

revlog.addgroup(): always use _addrevision() to add new revlog entries This makes parentdelta clone support pulling.

revlog._addrevision(): allow text argument to be None, build it lazily

changegroupsubset: use readdelta() fast path when delta is against a parent

run-tests: handle .tst not ending with an LF

minirst: small code cleanup