Variables names display in model view in OpenFLUID-Builder

* Added transparent background to variables names in model view

(references OpenFLUID/openfluid#246)
Fix of project checking in OpenFLUID-Builder

* Fixed check of attributes production/requirements

(references OpenFLUID/openfluid#246)
Rough view for spatial domain in OpenFLUID-Builder

* Added table for view of spatial domain information
* Cleaned code

(references OpenFLUID/openfluid#246)
Rough view for datastore in OpenFLUID-Builder

* Added table for view of datastore information
* Cleaned code

(references OpenFLUID/openfluid#246)
Ability to create/open a project in OpenFLUID-Builder

* Added ability to open or create a project 
  when a project is already open
* Cleaned code

(references OpenFLUID/openfluid#246)
Update of About dialog

* Updated switch link for license/credits

(references OpenFLUID/openfluid#246)
Fix of recent project opening in OpenFLUID-Builder

* Fixed ability to open a recent project when a project is already open
* Cleaned code

(references OpenFLUID/openfluid#246)
Zoom capabilities in model view in OpenFLUID-Builder

* Added zooming using the mouse wheel
* Added buttons for zoom fit and reset 
* Added ModelView class for management of the graphical model view

(references OpenFLUID/openfluid#246)
Fix of install configuration in CMake files for OpenFLUID-Builder

(references OpenFLUID/openfluid#246)
Fix of OpenFLUID-Builder toolbar stylesheet, for MacOSX compatibility

(references OpenFLUID/openfluid#246)