P4A_Base_Mask: extension of P4A_Mask, very useful to create a mask for your application with some cool features.
default P4A_Frame is instanced, with width equal to 730px. Use this frame to anchor all the widgets needed
a P4A_Message with “warning” icon, use this to print out warnings
a P4A_Message with “info” icon, use this to print out info messages
mandatory fields easy checking