v0.6.6 added smart mode for charge points without PV

A small feature release.

New features

• Smart mode for charge points without PV. The mode selector now mirrors evcc's own behaviour for setups without a PV system. When a charge point is marked via no_pv, Min+PV is hidden and the PV mode is replaced by a single Smart mode whenever a dynamic electricity tariff is configured. "Smart" still sets the same underlying pv charge mode (evcc only renames it, because without solar the charging is driven by electricity tariffs instead of PV surplus); only the label and icon change. If no dynamic tariff is available, only Off / Now are offered, as before. A dynamic tariff is detected via the tariff_grid / tariff_co2 sensor. Closes #154.