Change field labels for docs comments form

Clearly indicate what's subject, what's body, and that it's sending an
email.

pgweb/docs/forms.py

@@ -2,7 +2,8 @@ from django import forms
 
 class DocCommentForm(forms.Form):
 	name = forms.CharField(max_length=100, required=True)
-	email = forms.EmailField(max_length=100, required=True)
+	email = forms.EmailField(max_length=100, required=True, label="Your email")
 	shortdesc = forms.CharField(max_length=100, required=True,
-								label="Short description")
-	details = forms.CharField(required=True, widget=forms.Textarea)
+								label="Email subject")
+	details = forms.CharField(required=True, widget=forms.Textarea,
+							  label="Email body")

pgweb/docs/views.py

@@ -162,4 +162,5 @@ def commentform(request, itemid, version, filename):
 		'form_intro': template_to_string('docs/docsbug.html', {
 			'user': request.user,
 		}),
+		'savebutton': 'Send email',
 	})