Delete KOI-254.xml

Duplicate of Kepler-45
Update Kepler-74.xml

Alternative names added.
Delete KOI-200.xml

Duplicate of Kepler-74
Merge branch 'patch-29' of github.com:jaroslavmerc/open_exoplanet_catalogue into jaroslavmerc-patch-29
Merge branch 'patch-28' of github.com:jaroslavmerc/open_exoplanet_catalogue into jaroslavmerc-patch-29
Merge branch 'patch-30' of github.com:jaroslavmerc/open_exoplanet_catalogue into jaroslavmerc-patch-29
Readded description.