Added expansion vessel and updated documentation of ConservationEquation.

This is for #42.
Added expansion vessel reference results.

This is for #42.
Merge branch 'master' into issue42_expansionVessel
Merged actuators from Buildings to Annex60 library.

This is for #51.
Merge pull request #47 from iea-annex60/issue42_expansionVessel

Merge Issue42 expansion vessel - tested in Buildings library and no objections from my side
Merge pull request #52 from iea-annex60/issue51_actuators

Merged actuators from Buildings to Annex60 library. All examples work and code looks correct
Added missing packages to package.order.
Corrected malformed documentation which caused model not to load in OpenModelica.
Merge branch 'master' into issue54_cpWater