diff: pass a diff hunks filter function from changeset_printer to patch.diff()
We add a 'hunksfilterfn' keyword argument in all functions of the call
stack from changeset_printer.show() to patch.diff(). This is a callable
that will be used to filter out hunks by line range and will be used in
the "-L/--line-range" option of "hg log" command introduced in the
following changesets.
BasedOnStyle: LLVM
IndentWidth: 8
UseTab: ForIndentation
BreakBeforeBraces: Linux
AllowShortIfStatementsOnASingleLine: false
IndentCaseLabels: false
AllowShortBlocksOnASingleLine: false
AllowShortFunctionsOnASingleLine: false