[B.A.T.M.A.N.] Correct smaller typographical errors

After the infamous "neighbo(u)rs" patches, I wanted to send some more release critical fixes. :)

There are just some possible problems found by Debian's lintian (or by me after searching for more typos) which could easily fixed by upstream. No big changes, but some letters exchanged.

There is also some sentence in the batman manpage which should maybe changed. Maybe a native english speaking person could check if it is valid and understandable.

"B.A.T.M.A.N tries to find the best available connection by watching the uplinks throughput and the link quality."