small improvement to worksheet editing
allow editing (importing) worksheets from a file rather than editor
allow users to use -B to base the bundle off of a bundle with the same name
allow mimic/macro to take no output bundles, in which case we process everything downstream of the input(s)
use real yaml, support looking deeper into a table value
added a new 'search' directive inside worksheets to allow displaying dynamic tables
support searching by dependencies and dependencies/<child path>
update examples to make streamlined, more general sugar for running commands
make remote bundle client consistent with allow_symlinks
allow mimic --shadow, which adds new bundles right after the corresponding old bundles in the proper worksheets
allow cl mimic a b a, so we can easily rerun an experiment
allow users to enter in CLI commands ('// rm' or '// edit -n new_name') in the worksheet, which get processed when the worksheet is saved
add --worksheet_spec to most commands so we can perform them relative to a worksheet; allow arbitrary CLI commands to be run from a worksheet
handle quoting of commands in worksheets
add get_worksheet_uuid to RemoteBundleClient
allow single quotes in encoding sequence of tokens; fix mimic to not make too many new bundles
Merge pull request #79 from codalab/pliang

make worksheets almost fully functional on the CLI side of things
updated workers to support kill command and remote machines
removed paramiko dependency, fixed remote execution issues
moved machine defs into new directory