Fix Temperature Quantities and Scales, fix om:hasScale

[jmkeil]

This PR solves issue #85 and #13.

Changes:

• fix domain of has scale
• fix restrictions of the temperature and its subclasses regarding the use of has unit and has scale
• add missing quantity om:KelvinTemperature
• add alternative label for thermodynamic temperature: absolute temperature
• add alternative label for thermodynamic temperature scale: absolute temperature scale
• use owl:oneOf in temperature quantities to make the singleton temperature scale helper classes unnecessary
• remove the singleton temperature scale helper classes (Celsius temperature scale, Fahrenheit temperature scale, Rankine temperature scale, Réaumur temperature scale) (not instances!)
• associate instances of thermodynamic temperature scale using rdf:type instead of owl:oneOf
• associate all temperature scales (Celsius scale, Fahrenheit scale, Kelvin scale, Rankine scale, Réaumur scale) with thermodynamic temperature scale (instead of only Kelvin scale)
• remove Temperature_scale (usages replaced with thermodynamic temperature scale)