Issue276 building2thermalzones

This closes #276 (closed). This PR finally moves HighOrder and Components from Buildings package, mainly to ThermalZones.HighOrder. Weather is moved to BoundaryConditions.WeatherData.Old, since it will be deprecated in some point in time, but currently too many people still rely on that model. InternalGains is moved to Utilities, since we have here already sources like IdealHeaterCooler. This PR comes with a conversion script to modify existing dependent models. Since it is called if somebody is using AixLib in version 0.6.0, no matter to what the new version is, I kept 0.6.0 as the current version number. When we release the next version, we can easily switch to whatever version number we like. We only need to consider in-between releases and raise the number in the conversion script call in package.mo of AixLib. Otherwise, if somebody e.g. uses version 0.6.1, the conversion script won't be called. I created a test file with all moved files here: https://gist.github.com/mlauster/79b5768e4909716ba826e77f82645e75 This can be used to test if the conversion script works. Just checkout the branch and load this file in Dymola. Afterwards, all icons of all models in the test file should be visible.