Since Go 1.7, context is a standard package. Since Go 1.9, everything
that is provided by "x/net/context" is a couple of type aliases to
types in "context".
Many vendored packages still use x/net/context, so vendor entry remains
for now.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
When plugins have a positive refcount, they were not allowed to be
removed. However, plugins could still be disabled when volumes
referenced it and containers using them were running.
This change fixes that by enforcing plugin refcount during disable.
A "force" disable option is also added to ignore reference refcounting.
Signed-off-by: Anusha Ragunathan <anusha@docker.com>
