Add explanation about WIP status to MR form.

app/assets/stylesheets/generic/forms.scss

@@ -89,7 +89,6 @@ label {
   @include box-shadow(none);
 }
 
-.issuable-description,
 .wiki-content {
   margin-top: 35px;
 }

app/views/projects/_issuable_form.html.haml

@@ -11,6 +11,15 @@
   .col-sm-10
     = f.text_field :title, maxlength: 255, autofocus: true,
         class: 'form-control pad js-gfm-input', required: true
+
+    - if issuable.is_a?(MergeRequest)
+      %p.help-block.hint.col-sm-12
+        - if issuable.work_in_progress?
+          This merge request is marked a <strong>Work In Progress</strong>.
+          When it's ready, remove the <code>WIP</code> prefix from the title to allow it to be accepted.
+        - else
+          To prevent this merge request from being accepted until it's ready, 
+          mark it a <strong>Work In Progress</strong> by starting the title with <code>[WIP]</code> or <code>WIP:</code>.
 .form-group.issuable-description
   = f.label :description, 'Description', class: 'control-label'
   .col-sm-10

app/views/projects/merge_requests/show/_mr_accept.html.haml

@@ -6,7 +6,7 @@
     .automerge_widget.cannot_be_merged.hide
       %strong This request can't be merged automatically. Even if it could be merged, you don't have permission to do so.
     .automerge_widget.work_in_progress.hide
-      %strong This request can't be merged automatically because it is marked a Work In Progress. Even if it could be merged, you don't have permission to do so.
+      %strong This request can't be accepted because it is marked a Work In Progress. Even if it could be accepted, you don't have permission to do so.
     .automerge_widget.can_be_merged.hide
       %strong This request can be merged automatically, but you don't have permission to do so.
 
@@ -57,11 +57,11 @@
         %i.fa.fa-warning
         Accept Merge Request
        
-      This usually happens when git can not resolve conflicts between branches automatically.
+      This usually happens when Git can not resolve conflicts between branches automatically.
 
   .automerge_widget.work_in_progress.hide
     %h4
-      This request can't be merged because it is marked a <strong>Work In Progress</strong>.
+      This request can't be accepted because it is marked a <strong>Work In Progress</strong>.
 
     %p
       %button.btn.disabled{:type => 'button'}
@@ -69,7 +69,7 @@
         Accept Merge Request
       &nbsp;
 
-      When the merge request is ready, remove the "WIP" prefix from the title to allow it to be merged.
+      When the merge request is ready, remove the "WIP" prefix from the title to allow it to be accepted.
 
   .automerge_widget.unchecked
     %p