add ability to have a selectable prompt from the select dropdown

README.md

@@ -184,15 +184,16 @@ The select element requires more options (see [{{one-way-select}}](https://githu
 - `optionLabelPath`
 - `optionValuePath`
 - `optionTargetPath`
-- `includeBlank`
+- `prompt`
 
 ```Handlebars
 {{f.input
   type         = "select"
   label        = "Country"
   name         = "country"
   options      = countries
-  includeBlank = "Please choose..."
+  prompt = "Please choose..."
+  promptIsSelectable= = true
   }}
 ```
 

addon/templates/components/validated-input.hbs

@@ -38,18 +38,19 @@
   {{#if (eq type "select")}}
 
     {{one-way-select
-      value            = (or value (get model name))
-      options          = options
-      optionLabelPath  = optionLabelPath
-      optionValuePath  = optionValuePath
-      optionTargetPath = optionTargetPath
-      name             = name
-      class            = config.css.control
-      update           = (action "update")
-      focusOut         = (action "setDirty")
-      includeBlank     = includeBlank
-      disabled         = disabled
-      multiple         = multiple
+    value               = (or value (get model name))
+    options             = options
+    optionLabelPath     = optionLabelPath
+    optionValuePath     = optionValuePath
+    optionTargetPath    = optionTargetPath
+    name                = name
+    class               = config.css.control
+    update              = (action "update")
+    focusOut            = (action "setDirty")
+    prompt              = prompt
+    disabled            = disabled
+    multiple            = multiple
+    promptIsSelectable  = promptIsSelectable
     }}
 
   {{else if (eq type "radioGroup")}}