Added image cropper widget for user images.

* Also added a validator for processed images.
Fixes/Tweaks to HRM/Org based on IFRC UAT: Stay within Tabs where possible. Fix boundary for SG, Fix empty CheckboxesWidget, Add Facility Type button, Ensure XLS output doesn't crash when sheet_name too large
Complete inv_warehouse_rheader => inv_rheader, revert re-introduction of _next (dangerous for its side-effects), remove unnecessary delete-action override instead to stay in tab.
merge aviraldg: OSM settings fix
Fix autodelete: the linked table may use an alias, so re-define.
Remove more action-button overrides (native=False prevents the breakout to doc/document).
match_req shows Role Manager tab when it should, project_project_onaccept works from a tab (non-3W mode)
Merge branch 'master' of git://github.com/nursix/eden
Bug fix label lookup for keys.
Fix CSV import for Staff & Facilities. Disable organisation/project Embed until Widget fixed
Fix indents
Fix AddPersonWidget
Only JSON.
Merge branch 'master' of git://github.com/nursix/eden
Render images in resource based PDF exports (fixes #1371)
Merge pull request #360 from aviraldg/fix-1371

Render images in resource based PDF exports (fixes #1371)
Merge pull request #354 from aviraldg/profile-image-crop

Added image cropper widget for user profile image.
Merge branch 'master' of git://github.com/flavour/eden
Merge branch 'master' of git://github.com/flavour/eden
Reactivate unit tests.