[Libreoffice] ccache support

[Tor Lillqvist]

If one of us (cloph) strongly feels that we should use # comments in configure.in and not dnl comments (well, keywords), and most others (?) (including me) are indifferent, why don't just change them all in one go then?

I wonder if there is some cases where the dnl keyword can not just be changed to # without changing the semantics of the autoconf/shell code?

--tml