The scoutfs backend is only supported on 64bit linux. This corrects
the build constraints to only supported linux arch, and prevents the
incompatible import for unspported arch.
We also need to adjust the body limit setting on 32 bit since this
is an int, and our default limit will overfow on 32 bit.
This adds a context to the backend interface calls so that the backend
can enable request cancellation. This change isn't acutally implementing
any backend handling, but just putting the pieces into place to pass the
context to the backend.
The aws cli will send range gets of an object with ranges like
the following:
bytes=0-8388607
bytes=8388608-16777215
bytes=16777216-25165823
bytes=25165824-
The last one with the end offset unspecified just means the rest of
the object. So this fixes that case where there is only one offset
in the range.
