Array: minor __str__ updates
Plot.add_colorbar: minor bug fixes
Channel: doc updates and fix name setting

    - a bit of a hack to handle the H1:LDAS-STRAIN,rds special case for
      S6 data in NDS
timeseries.core: multiple changes

    - rebuild TimeSeriesDict.fetch to be more readable
    - added hack to fall back to iterate if fetch fails with a 'too much
      data' error, expect fix to nds2-client
    - a few doc changes
    - changed TimeSeries.epoch to use GPS in UTC scale directly
setup.py: install_requires changes

    - added dateutil
    - added specific versions for numpy, astropy, and matplotlib