segments: added segment query utils
triggers: added trigger query utils
metrics: fixed type error in deadtime
segments: added reading from lists (not Cache)
metrics: fixed decorators, minor arg edits

    - use decorator package, not just functools
    - metric methods should only take the arguments as required, and not
      allow for lazy passing of triggers, etc
Metric.needs_triggers: added extra property

    - switch to check whether this metric function needs triggers or
      just segments
get_triggers: bug fixes
setup: add decorator package requirement
gwvet: added command-line util

    - only 'flag' mode just now, check union performance of one or more
      segment lists against some triggers
Metric: whitespace and doc changes only