add m_flow_nominal to PartialHeatSource.mo for the smoothMax + add limit to release.
add noEvent to release, change release so that no power when release = 1, change k parameter to 4 as its dimension is fixed by the size of X + put the variables of function in protected part.
rename models, split package HeatSources.mo into separeted models file, add constrained by for repleceable HeatSources.mo
add an on/off interface and the possibility to avoid events in the modulation hysteresis.
Merge branch 'issue45BoilerModel' of https://github.com/open-ideas/IDEAS into issue45BoilerModel

Conflicts:
	IDEAS/Fluid/Production/BaseClasses/PartialHeatSource.mo