Merge pull request #1 from politeauthority/acl

Acl
Fully removing the generic chart method, for specific weather / water
Merge branch 'master' of https://github.com/politeauthority/garden_pi
Updates to our main cron job, adding a few more alert hooks with failed sensor readings on the i2c bus, this is still needed on the GPIO on the sht1x error reading
Quick fix to help first time installs with empty db cells