Changed the odid MediaEngine livesim control variables to simplify live mode configuration

The ODIDLiveSimulator variables/semantics are unchanged. But the resource.info
 variables for configuration are simplified/clarified.

The new per-resource live config variables are:

 live-sim-mode=[off|live|recording|tsb|timely-range]

  live: Simulates a strict live stream that starts on first resource access.
        No random access will be exposed, S0/SN are set. All reads will be
        paced. If/when the end of the on-disk content is reached, the
        resource becomes unstreamable (until reset).

  recording: Simulates a recording that starts on first resource access
             and allows full random access to the recorded content.
             Full time-/byte-based access is supported, S0-increasing will
             be unset, SN-increasing will be set, res@size/@duration are
             unspecified, and seek response durations will be unspecified.
             Attempts to read past the live point will be paced.
             If/when the live point encounters the end of the on-disk content,
             the resource will become a completed recording. SN-increasing
             will be unset, res@size/@duration will be specified, and seek
             response durations will be specified (until reset).

  tsb: Simulates a TSB (time-shift buffer) that starts on first resource
       access and allows limited random access to a continuously-moving
       range from the live point backward. Limited time-/byte-based access
       is supported, SN/SN-increasing will be set, res@size/@duration are
       unspecified, seek response durations will be unspecified, and the
       availableSeekRange response header will reflect the available seek
       range. Attempts to read past the live point will be paced. And
       If/when the end of live point encounters the end of the on-disk content,
       the resource will become a completed recording. SN-/S0-increasing
       will be unset, res@size/@duration will be specified (to the amount
       of content in the TSB), and seek response durations will be specified
       (until reset). Note: live-range-duration must be set.

  timely-range: Simulates timely access to a fixed range of content. The
       availableSeekRange response header will reflect the timely seek
       range that starts at live-start-time-offset and ends at
       live-start-time-offset+live-range-duration (or the end of the on-disk
       content). Access to content outside the range will encounter a delay
       defined by live-nontimely-delay. Note: live-range-duration must
       be set.

 live-start-time-offset=<uint>

  Start time, in seconds. For live-sim-mode=live|recording|tsb, this will
   be the initial live time at first content access (it will appear that
   this amount of time has elapsed). For live-sim-mode=timely-range, this
   is the beginning of the timely access range.

 live-range-duration=<uint>

  Range duration (when live-sim-mode=tsb|timely-range) (in seconds)

 live-nontimely-delay=<uint>

  Time delay for content requests outside the defined time range (when
   live-sim-mode=timely-range) (in ms) (default 1000)

Live mode "timely-range" is not supported as-of-yet (LOP mode 1). But
 laid the groundwork.

 The "limited-operation-mode" is removed. The mode is set according to the
  value of the "live-sim-mode" setting. (mode 0 for TSB and 1 for
  "timely-range")

 Some livesim variables are made more generic (removed "tsb" from the
  names).

 TBD: Sim time doesn't need to advance, ODIDDataSource needs to use
      live-nontimely-delay when request range is outside timely range

Ran tests with live-sim-mode set to "live", "tsb", and "recording".
 Checked res blocks and performed http requests with and without
 time range requests.