record: minor refactoring of dorecord
It prepares the way for introducing the flag to reverse hunk selection
record: change arguments of curses recording function
This way the arguments are the same for both curses and non-curses versions.
record: change interface of the filtering function
This way filtering functions accept chunks and return chunks
filectx: add a repo accessor
This is similar to
a07314472a80 in motivation. All contexts now have this
method, so the rest of the 'ctx._repo' uses can be converted without worrying
about what type of context it is.
run-tests: ignore ENOENT failures when removing old .err results
When the same test runs in multiple threads and the previous run was a
failure, the threads can race to delete the error output. This fixes
that.