Better handling of image creation error

show graphite URL for debugging so we are able to see graphite error
message if there is one.
expire headers also for error message
removed closing php tags from non-view files

avoid generating output that can destroy for example image data
Merge pull request #1 from cebe-cc/image-error-handling

Better handling of image creation error
Merge pull request #2 from cebe-cc/php-tags

removed closing php tags from non-view files
Print a small white title under each graph card so it's easy to find on the page
Merge branch 'master' of https://github.com/hyves-org/graphsky
Add softirq to cpu graph
Changed colors of mysql graph
Show all disks in virt_disk_ops graph.
Matched colors of virt_disk_ops and disk_ops
Adding MIT license file
Fix for displaying real host/cluster name
Removed unnecessary div
Added missing graph_size in graph links
Adding a default text when no env is selected
Fix for error about missing option_values variable
New sticky menu bar, and new CSS based mobile view.
Couple of other minor UI fixes and tweaks.
Updated smallmenu button and added slideout menu button
New screenshots, including mobile view
Update README.md
Added other common HDD names in regex