Removed weaBus.sol for OpenModelica.

Removed the expandable connector sol from the expandable connector
weaBus as this construct does not work in OpenModelica.
Deleted the expandable connector SolarSubBus.
Renamed the following variables on the weather data bus:
sol.zen -> solZen
sol.dec -> solDec
sol.alt -> solAlt
Deleted SolarSubBus.mo
Bugfix for sky cover if not obtained from weather file.
Merge branch 'master' into openmodelica-weather
Set Tolerance=1E-8.
Change der_temperature_u for OpenModelica.

This commit changes the function argument to use single elements rather
than a record.
Merge branch 'openmodelica' into openmodelica-weather
Updated release notes and conversion script.

This is for the update of the weather data bus.
Merge pull request #301 from lbl-srg/openmodelica-weather

Openmodelica weather bus compatibility
Reformulated glass calculation for OpenModelica.
Corrected wrong html syntax
Removed redeclare.
Corrected type error.