rebased OmeroPy/src/path.py onto upstream version 5.2
path.py: walk: "errors" now defaults to "ignore", consistently with os.walk
path.py: listdir: added "unreadable_as_empty" kwarg
updated lib/licenses
Fix update in jsTree when Project / Dataset renamed
Handle Figure scripts with cross-group search results
Handle cross-group OME-TIFF export, E.g. from search results
Fix 'duplicate headers' bug in download original image
added test module for custom modifications to path.py
Merge remote-tracking branch 'origin/develop' into bugfixes_for_5_0_4
Merge remote-tracking branch 'origin/develop' into bugfixes_for_5_0_4

Conflicts:
	components/tools/OmeroWeb/omeroweb/webgateway/views.py
UI rearrangement

Moved color mode (rgb/grayscale) button and channel selection
buttons from the left-hand side of the preview to below
the preview.
Moved color picker out of the popup menu
Just did some clean up
Renamed some menu items and buttons
Removed unneccessary code
Fixed problem with greyscale button
Changed color picker button to label
Trim the end of the text of the ChannelButton if it doesn't fit
Added Copy/Paste (paste not working yet)