Merge branch 'maint'

Merge branch 'maint'

* maint:
  Fix clang build warning "shift count >= width of type"
  Clean up stale files in internal tempdir once an hour
  Add signal handler to clean up temporary files at unexpected program exit
  Don't needlessly allocate empty counter_updates data in stats_flush()

Conflicts:
	ccache.c
	manifest.c
	stats.c