Projects management

Projects can be deleted and closed with a context menu. Projects can be moved changing path in Properties. Initial directory when file choosing now is the home directory.
Friday coffee

* TSV Reader now opens on main window.
* Project Properties are shown on the left bottom area. 
* ProjectListener interface to listen for changes in Project properties.
* OS class has been branched: file related methods are kept in FileManager.
* FileSelector.fxml is smaller (it had redundant hbox on vbox on hbox)
* FileSelector has been documented
TO DO:
* apply ProjectListener to ProjectInfo.