fix failing test
pass boot time through to pikelets
don't pluralise singular time periods
Merge pull request #220 from ali-graham/172_fix_identify_boot_time

Fix jabber identify boot time, pluralisation of singular time periods.
Update CHANGELOG.md
cherry-pick fix for change in thin internals
show maintenance times in web check page, allow re-ack through filter
Merge branch 'master' of github.com:flpjck/flapjack into 159_surface_ack_duration