[Libreoffice] default build verbosity

hi all,

a recurring problem with remote debugging newbie build problems is that
the default build is silent.

i wonder if it would make sense to change that:
with default configure invocation, build system outputs the full command
to the terminal/log, and there is an explicit configure option to
silence the build.

so when newbies pastebin their broken build, it's much easier for
developers to spot wrong command lines without wasting time writing a
lot of pointless mails and such.

actually for tinderbox builds there could also be advantages (though it
would also make the logs a lot bigger).

on the other hand, experienced developers can just put the configure
option in their autogen.lastrun as a one-time cost and won't be bothered
much.

regards,
 michael