Moving release archives for BSF, BCEL, JCS from Jakarta to Commons

At present, BSF, BCEL and JCS downloads still use /dist/jakarta/<proj>.

I've just started the process of moving JMeter files to the new JMeter
TLP, so I thought I might as well do the same for the remaining
Jakarta downloads.

This is what I propose for the Commons moves:

- copy (cp -p) archives, sigs, hashes from /dist/jakarta/<proj> to
/dist/commons/<proj>
- add redirect for /dist/jakarta/<proj> to
http://ww.apache.org/dist/commons/<proj>
(this only affects www.apache.org, not the 3rd party mirrors)

Wait a day or two to allow the mirrors to catch up.

Next stages are:

- update <proj> download page to use /dist/commons/<proj>
- delete /dist/jakarta/<proj>

At some later point the archives need to be tackled, but that might
involve infra.

I think that's it; if anyone can spot any errors in the process please advise!