sparco fields organized in show hide groups

[buthanoid]

• splitted display in three functions: default, mira, sparco
• default just print the keywords (label + field) by calling function addFormKeyword
• mira print its bandwitdth smearing keywords. It also uses a ShowHideComponentsButton, which is a small class associating a toggle button to a list of components. Toggling the button show/hide the associated components. So mira's two smearing keywords are shown/hidden by the button. We also display any other keyword by calling default display
• sparco print is like mira, there is a show hide for each model. it also calls mira display since sparco is an extension of mira
• getLabel function is added to provide human friendly labels
• added a spinner (up and down arrows) on the selection of number of models