Update man pages for scala and scalac.

They had fallen quite a bit behind the output of
"scalac -X" and "scalac -Xshow-phases".

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I always have to remember to query scalac directly instead of using the man page; well, not anymore :-)

Here is the resulting html man page : https://dl.dropboxusercontent.com/u/46938538/static/man/html/scalac.html
And the old one for comparison: http://www.scala-lang.org/files/archive/nightly/docs/manual/html/scalac.html