setup.py: copied setup infrastructure from GWpy
setup.py: restore share/ file install
PlotList: deleted unused class
docs: make into /build/sphinx

    - matches default from python setup.py build_sphinx
config.py: added method to convert ConfigParser

    - from_configparser will convert ConfigParser to GWSummConfigParser
      subclass
    - added InterpolationMissingOptionError (not in
      configparser.__all__)
gw_summary: don't require [states] or [html]

    - now handles missing sections gracefully
plot.registry: allow non strings in register_plot
state.registry: improve docs, add get_states
state: improve docs, etc
config: preserve case in INI files
plot: renamed classes, improved documentation
docs: added more docs
Merge branch 'master' of https://github.com/gwpy/gwsumm

Conflicts:
	MANIFEST.in
	bin/gw_summary
	gwsumm/config.py
	gwsumm/plot/builtin.py
	gwsumm/plot/core.py
	gwsumm/state/__init__.py
gw_summary: allow missing ifo if not needed
docs: improved make arguments
ArchiveStateTab.from_ini: added gps times
.gitignore: added /docs/api
SummaryState.hours: implemented time-based states

    - can configure hour-of-the-clock states as follows

      hours = A-B,C-D,tz

      where A,B,C,D should be integers representing hours, e.g. 2-6 will
      configure hours 2 through 6. The 'tz' is one of

      - 'utc'
      - 'local': local timezone of --ifo
      - IFO prefix e.g. 'H1': local timezone of that IFO
plot: allow gap ignoring in join
get_channel: added timeout kwarg