Refactored directory handling a bit in fuse to better accomodate other virtual
directory types, and added virtual directories for tags (untested).  Existing
tests pass, need to write new tests for tag directories.
Added run_test_server helper module for Python SDK that runs API server in test
mode and provides access to fixtures and API tokens.
Merge branch 'master' into 2035-arv-mount-tags-folders
Created a seperate arvados-fuse-driver package.
Finished implementing FuseTagsTest, fixed bugs in arv-mount, test passes.
Added websockets support to Python SDK, with integration test.  Also built out
runner script for running test server from python.
Refactored freshness/updating to be more generic for different virtual
directory types.  Added polling based on timeout as an alternative to
websockets.  Refactored tests a bit.
Merge branch 'master' into 2035-arv-mount-tags-folders
Merge branch 'master' into origin-2035-arv-mount-tags-folders
Added PyYAML to requirements.txt
Merge branch 'master' into origin-2035-arv-mount-tags-folders
Adding support for groups and viewing arvados objects as files (serialized
json).  Work in progress.
Improved fresh/stale handling with base class, added property fuse inode cache
invalidation.  Added common merge function for handling directory updates.
arv-mount now daemonizes by default.
Added test for group mount.  Passes.
Eliminated build.sh and sed in favor of a common setup_header.py script which
call popen to get the git revision directly.  Removed spurious server_pid > 0
and added except Execption: on run_test_server.py.
Merge branch 'master' into origin-2035-arv-mount-tags-folders
Merge branch '2035-arv-mount-tags-folders' into origin-2035-arv-mount-tags-folders
Merge branch 'origin-2035-arv-mount-tags-folders'

Conflicts:
	sdk/python/bin/arv-mount