This string is the base CSS class name applied to a FormItem (or some part of a form item). The style name will be
 modified as the 'state' of the form item changes. Specifically:
 - If 
FormItem.showPending is true, when the current value
 differs from the     value that would be restored by a call to DynamicForm.resetValues(), this style     will have the suffix
 "Pending"  appended to it.  - If 
FormItem.showFocused is true, when the form item receives focus, this     style will have the suffix "Focused" appended
 to it.  - If 
FormItem.showErrorStyle is
 true, if the form item has errors, this     style will have the suffix "Error" appended to it.  - If 
FormItem.showDisabled is true, when the form item is
 disabled, this     style will have the suffix "Disabled" appended to it.  - Finally, if 
FormItem.showRTL is true, when the form item is in RTL
 mode, this     style will have the suffix "RTL" appended to it. 
 So for example if the cellStyle for some form item
 is set to "formCell" and showFocused is true, when the form item receives focus, the form item's cell will have the
 "formCellFocused" style applied to it.