Merge pull request #1900 from will-moore/ajax_contentType_11821

Ajax content type 11821
Merge pull request #1890 from jburel/unit-issue

Fix units if value is 0.0
Merge pull request #1898 from jburel/admin-fix

Admin fix
Review failing append/remove unit tests
Fix polyline unit test
Fix createPolyline x, y ordering
Also fix the createPolygon() function and the corresponding unit test
Check the network every 5s
Remove static since we only one checker (gateway)
Fix the timeout value.
Remove private method so only used.
Set current time to avoid double check when created.
Set the init value of last check to current time.
Remove unused method.
Reduce the number of call to check network.
Remove reflective code since min Java is 1.6
Rename test and helper classes to conform to pytest naming rules.
Do not allow to run the split figures on big images.
Fix omero config subcommands description by using parser.add()
Add append and remove to the subcommand list in test_prefs.py