Previously, regex-matching paths on windows would, in some cases, require four
backslashes ('\\\\') to escape a single path separator. That's just too much.
With this commit, regex transforms now use '/' instead of '\' as path separator,
meaning rules can more easily be shared between platforms (although they are not
guaranteed to be 100% compatible since on Windows, '\' is still recognized as a
path separator).
To make rules more intuitive to write, local relative paths are now also printed
with '/' as path separator on Windows. Since Windows also accepts '/' as path
separator, this change doesn't really affect other rules that parse their sides
as paths.
Using the stdlib's http.cookie module, cookies are now stored as one
"Set-Cookie" header per line. Previously, the aiohttp.CookieJar's save() and
load() methods were used (which use pickling).
ILIAS apparently changes the order of the fields as it sees fit, so we
now try to parse *every* column, starting at from the right, as a date.
The first column that parses successfully is then used.
