This adds a context.Context parameter to NewFs and related calls.
This is necessary as part of reading config from the context -
backends need to be able to read the global config.
1. adds SharedOptions data structure to oauthutil
2. adds config.ConfigToken option to oauthutil.SharedOptions
3. updates the backends that have oauth functionality
Fixes#2849
For a certain class of broken or missing image Google Photos puts an
image in the error message.
Before this fix we blindly chucked it into the error message.
After this fix we replace it with some sensible text.
This adds a bit of missed locking around the uploaded info to fix the
concurrent map write.
All the other accesses have locking - this one must have got missed.
This fixes a crash on the google photos backend when an error is
returned from the rest.Call function.
This turned out to be a mis-understanding of the rest docs so
- improved rest.Call docs
- fixed mis-understanding in google photos backend
- fixed similar mis-understading in onedrive backend
