Add new "changed" function

This function checks if a metric has changed and returns 1 when it changed else 0
Merge pull request #842 from ojilles/0.9.x

0.9.x backport of documentation updates
Minor fix for Vagrant+Syntesize docs
Allow metric finder to return jsonp objects

Needed for cross-domain ajax calls

Fix jsonp response format
Merge pull request #845 from deniszh/0.9.x_doc_fix

Minor fix for Vagrant+Syntesize docs, backport pull request 844 to 0.9.x.
Merge pull request #847 from ojilles/0.9.x

Documenting that you can use alpha values for colors in colorList and bg...
Rework of 'query-bulk' implementation for 0.9.x

Please see issue #378, I just reworked for latest 0.9.x branch and made configurable. Corresponding change for carbon was merged by @mleinart while ago - https://github.com/graphite-project/carbon/pull/132
Replacing #824.
Backport of pr #495 to 0.9.x branch

Fixes issue #220
Merge pull request #851 from deniszh/0.9.x_HWA_fix

Backport of pr #495 to 0.9.x branch
Merge pull request #846 from kali-hernandez-sociomantic/jsonp

Allow metric finder to return jsonp objects
Merge pull request #850 from deniszh/0.9.x_query_bulk

Rework of 'query-bulk' implementation for 0.9.x
Merge pull request #530 from criteo/changed-function

Add new "changed" function
remove superfluous grid line for log scale, refs #389
Merge pull request #867 from obfuscurity/backport_log_scale_labels_fix

Remove superfluous grid line for log scale
backport user graphs sorting fix, refs #209
Merge pull request #869 from obfuscurity/backport_sort_user_graphs

Backport user graphs sorting fix to 0.9.x
backport fix for reloading graphs tree in ajax callback, refs #603
Merge pull request #871 from obfuscurity/backport_reload_graphs_tree_after_ajax

Backport fix for reloading graphs tree in ajax callback to 0.9.x
backport fix for wrong series.name in percentileOfSeries, refs #501
Merge pull request #873 from obfuscurity/backport_fix_percentileOfSeries_name

Backport fix for wrong series.name in percentileOfSeries to 0.9.x