Merge branch 'simplejson_upgrade' into merge/dev_5_1/latest

Conflicts:
	components/tools/OmeroWeb/omeroweb/decorators.py
	components/tools/OmeroWeb/omeroweb/http.py
	components/tools/OmeroWeb/omeroweb/webadmin/views.py
	components/tools/OmeroWeb/omeroweb/webclient/views.py
	components/tools/OmeroWeb/omeroweb/webgateway/views.py

Conflicts:
	components/tools/OmeroWeb/omeroweb/webadmin/views.py
	components/tools/OmeroWeb/omeroweb/webgateway/views.py