Remove warning to reflect changed --enable-debug intentions.

Instead of defaulting the configure's debug option to 'no' as
originally intended, it will now be split into separate debugging
and logging options.

git-svn-id: svn://daper.net/moc/trunk@2653 910807d9-36e0-0310-a014-e9ea483e2ba4
Warn of requiring an ISO C99 capable compiler after 2.5.

git-svn-id: svn://daper.net/moc/trunk@2654 910807d9-36e0-0310-a014-e9ea483e2ba4
Fix pointer arithemetic code identified by -Wpointer-arith option.

git-svn-id: svn://daper.net/moc/trunk@2655 910807d9-36e0-0310-a014-e9ea483e2ba4
Remove assertion and handle negative current time values elsewhere.

A negative time value may arise legitimately if the hardware buffer
still contains more samples from the previous file than have been
decoded from the next file.  How it should be handled depends on
who's doing the asking:

1. When used in seeking, ignore the seek request.  Given the short
   duration still buffered from the previous audio, it is most
   likely that a seek at this time represents the balance of
   multiple seeks from the previous audio so ignoring any seek
   beyond end of audio seems appropriate.  If it's a seek in the
   new file, then the delay between the user seeing the change and
   starting to seek has probably already seen the residual samples
   played anyway.

2. When obtaining the current time for display, return zero.  The
   user is already looking at the next audio and the duration into
   that is, in fact, zero.

3. When updating the bitrate list, do not perform the update.  It
   seems unlikely that a bitrate across two audio files or at the
   very end or beginning of an audio has any real value.

It was thanks to Ondrej Svoboda's MPRIS patch (node/496) that we
were able to find this bug.  For some reason that patch seemed to
trigger it consistantly.

Resolves: node/148 (MOC 2.4.0 crashes on FreeBSD 5.5)
          node/626 (Can't send() int to the server)

git-svn-id: svn://daper.net/moc/trunk@2656 910807d9-36e0-0310-a014-e9ea483e2ba4