Introduction of Qt based OpenFLUID-builder user interface

* Renamed Gtk based interface with -gtk suffix
* Added new Qt based structure

(references OpenFLUID/openfluid#246)
Better handling of the close event on OpenFLUID-Builder main window
Merge branch 'develop' into develop-qt
Replace of LibCurl by QtNetwork

* Updated CMake files
* Created FileDownloader class using QtNetwork
* Removed libcurl use
* Updated tests

(closes OpenFLUID/openfluid#198)
Replace of LibXml2 by QtXml

* Modified FluidXDescriptor methods
* Modified DistributionTables methods
* Updated CMake files
Merge branch 'develop' into develop-qt
Merge branch 'develop-qt' of https://github.com/chataignerm/openfluid into chataignerm-develop-qt
Merge remote-tracking branch 'upstream/develop-qt' into develop-qt
Merge branch 'develop' into develop-qt
Merge remote-tracking branch 'upstream/develop-qt' into develop-qt
Project opening in OpenFLUID-Builder with Qt

* Added the ability to open and run a project with rough error
management
* Refactored PreferencesManager using QSettings
* Refactored headers for spatial loops, with separated threaded loops
* Modified test name for gtk based tests
* Updated tests

(references OpenFLUID/openfluid#246)
Fix of main return in boost tests
Merge branch 'develop' into develop-qt
Merge branch 'fix-boost-tests' of https://github.com/chataignerm/openfluid into chataignerm-fix-boost-tests
Project creation in OpenFLUID-Builder with Qt

* Added the ability to create an empty project (without import)
* Added access to home directory in runtime environment
* Added default values in preferences manager
* Updated tests

(references OpenFLUID/openfluid#246)
Various fixes and improvements in OpenFLUID-Builder with Qt

* Fixed wrong return value when creating project
* Introduced real button box in new project dialog
* Added specific CMake configuration for Mac OSX
* Added official OpenFLUID icon in resources

(references OpenFLUID/openfluid#246)
Import feature when opening a project in OpenFLUID-Builder with Qt

* Added tool for recursive copy of directory contents
* Added mouse cursor set to wait when necessary
* Added clickable URL link in home widget

(references OpenFLUID/openfluid#246)
Recents project menu in OpenFLUID-Builder with Qt

* Added menu for recent projects
* Added limit for maximum number of recent projects

(references OpenFLUID/openfluid#246)
Recents project home panel in OpenFLUID-Builder with Qt

* Added list of recent projects
* Added class for label management of recent project
* Fixed recent projects list management

(references OpenFLUID/openfluid#246)
Run simulation dialog in OpenFLUID-Builder with Qt

* Added simulation worker thread and listener
* Added simulation dialog
* Cleaned code

(references OpenFLUID/openfluid#246)