Merge pull request #123 from atlasapi/mbst-4778-people-equivalence

MBST-4778 People Equivalence
Merge pull request #126 from atlasapi/mbst-6116-bt-featuredcontent

Mbst 6116 bt featuredcontent
add upcoming location predicate to simple Item
Merge pull request #127 from atlasapi/mbst-6077-pertinent-content

Add upcoming location predicate to simple Item
Add Full image support to channels.
- ImageBackground enum has changed to ImageTheme, and the enum's values have changed as well
- TemporalField has been refactored to use generics
- Channel/ChannelGroup history elements now base their equality on start time only, to allow
de-duping of history events with the same timestamp on output.
Alter theme value to be lower-case with underscores.
Ensure that ImageTheme enum has correct values, and set a default for getTitleForDate(), so that
errors are avoided when there is no title for a given date.
Cope with nulls in equality methods for historical channel / channel group entries
Create history entries with their start date (unfortunately it can't be a private final parameter, thanks
to JAXB), so that no entries have null start date.
Merge branch 'mbst-5686-ingest-pa-channel-logos' into stage