Fix user interface items:

[monaw]

• [x] disable 2.5 & 3D buttons
• [x] update gateway_file_display color to black after a file is chosen, currently light gray
• [x] center Welcome title
• [x] display red border for invalid parameters
• [x] display red border for invalid probabilities
• [x] remove space for Gateway upload Browse button and the display field
• [x] get "Reset parameters" button working
• [x] update "Reset data" button to reset all data parameters
• [x] make plotting error message red & bold
• [x] clear table data when user clicks on "Reset data" button
• [x] zone parameter must be [1,60]
• [x] try dropdown list for zone parameter
• [x] default zone to 11 (CA/AZ)
• [x] disable "reset parameters" button, input parameters & load data during plotting

[monaw]

using dropdown list for Zone parameter is a better UI but unfortunately it is rather long for 60 options and if we reduce the number of items shown (size), then the UI goes from a dropdown to a box instead, yuck: