Don't set Expires header for logs of unfinished builds/steps

Dependencies

• [2] KI423DCQ Stream logs if possible and remove size limit
• [3] SAIUFDP3 hydra: make sure viewing logs works when logs are bz2'd
• [4] Y6AHH4TH Remove the logfile and logSize columns from the database
• [5] ZH6B56XR Try harder to find build logs
• [6] LZVO64YG Merge in the first bits of the API work
• [7] 6F4UNDTC * Provide access to the raw, non-pretty-printed logfiles.
• [8] LBNVQXUB * Build the /build stuff in a separate controller.

Change contents

• replacement in src/lib/Hydra/Controller/Build.pm at line 122
  [3.1443]→[3.511:598](∅→∅)
  − showLog($c, $mode, $step->drvpath, map { $_->path } $step->buildstepoutputs->all);
  [3.1443]

  [3.1554]
  + showLog($c, $mode, $step->busy == 0, $step->drvpath,

  + map { $_->path } $step->buildstepoutputs->all);
• replacement in src/lib/Hydra/Controller/Build.pm at line 129
  [3.221]→[3.599:708](∅→∅)
  − showLog($c, $mode, $c->stash->{build}->drvpath, map { $_->path } $c->stash->{build}->buildoutputs->all);
  [3.221]

  [3.1923]
  + showLog($c, $mode, $c->stash->{build}->finished,

  + $c->stash->{build}->drvpath,

  + map { $_->path } $c->stash->{build}->buildoutputs->all);
• replacement in src/lib/Hydra/Controller/Build.pm at line 136
  [3.302]→[3.709:755](∅→∅)
  − my ($c, $mode, $drvPath, @outPaths) = @_;
  [3.302]

  [3.0]
  + my ($c, $mode, $finished, $drvPath, @outPaths) = @_;
• edit in src/lib/Hydra/Controller/Build.pm at line 160
  [2.387]

  [2.387]
  + $c->stash->{finished} = $finished;
• replacement in src/lib/Hydra/View/NixLog.pm at line 23
  [2.953]→[2.953:998](∅→∅)
  − setCacheHeaders($c, 365 * 24 * 60 * 60);
  [2.953]

  [2.998]
  + setCacheHeaders($c, 365 * 24 * 60 * 60) if $c->stash->{finished};