Save every model to a single file
Convert library to utf8 coding

Also, graphic representation of HeatConv has been changed to be compliant
with Modelica Spec. This is for #10 and #26
Change == false to if not

This solves #28
Clean up of UsersGuide

For #27
Clean up of UsersGuide del Conventions.mo

For #27
Merge pull request #29 from RWTH-EBC/issue10_utf8

Towards compatibility with OpenModelica