Add a note about copying limits

oioioi/problems/forms.py

@@ -104,7 +104,14 @@ class Meta(object):
 
 
 class ProblemsetSourceForm(forms.Form):
-    url_key = forms.CharField(label=_("Enter problem's secret key"), required=True)
+    url_key = forms.CharField(label=_("Enter problem's secret key"),
+                              help_text=_("Please note that the time and memory limits will be copied\
+                                          from the source problem. If they have been overriden\
+                                          in a specific contest, these settings will not be copied.\
+                                          If you want to copy the limits from a specific contest,\
+                                          please go the contest's problem list and use the 'Attach\
+                                          to another contest' option."),
+                              required=True)
 
     def __init__(self, url_key, *args, **kwargs):
         super(ProblemsetSourceForm, self).__init__(*args, **kwargs)

oioioi/problems/templates/problems/problemset-source.html

@@ -20,7 +20,7 @@
         <span class="help-inline">{{ error }}</span>
         {% endfor %}
         {% if form.url_key.help_text %}
-        <p class="help-block">{{ form.url_key.help_text }}</p>
+        <small class="help text-muted form-text">{{ form.url_key.help_text }}</small>
         {% endif %}
     </div>