Created validate_device_id() function
Added null check for $id
Merge pull request #257 from laf/issue-laf-16

Created validate_device_id() function
Fixed graphs / no graphs line break
Merge pull request #264 from laf/issue-laf-22

Fixed graphs / no graphs line break
Fixed user preference page to show devices allowed access
Merge pull request #265 from laf/issue-laf-24

Fixed user preference page to show devices allowed access
Changed incorrect MAX CF to MIN for rrd creation
Unset variables which were bleeding into other polling runs
Updated layout for delete device so it is consistent
Merge pull request #270 from laf/issue-laf-27

Updated layout for delete device so it is consistent
Merge pull request #267 from laf/issue-laf-31

[URGENT] Unset variables which were leaking into other polling runs
Merge pull request #266 from laf/issue-laf-30

[URGENT] Changed incorrect MAX CF to MIN for rrd creation
Fixed links for health graphs
Merge pull request #271 from laf/issue-laf-34

Fixed links for health graphs