Consolidate class names

common/lib/capa/capa/templates/textinput_dynamath.html

 ###
 ### version of textline.html which does dynamic math
 ###
-<section class="text-input-dynamath textinputdynamath capa_inputtype" id="inputtype_${id}">
+<section class="text-input-dynamath capa_inputtype" id="inputtype_${id}">
 
     % if preprocessor is not None:
-    <div class="textinputdynamath_data" data-preprocessor="${preprocessor['class_name']}"/>
+    <div class="text-input-dynamath_data" data-preprocessor="${preprocessor['class_name']}"/>
     <div class="script_placeholder" data-src="${preprocessor['script_src']}"/>
     % endif
 

common/lib/xmodule/xmodule/js/src/capa/display.coffee

@@ -327,12 +327,12 @@ class @Problem
 
   inputtypeSetupMethods:
 
-    textinputdynamath: (element) =>
+    'text-input-dynamath': (element) =>
       ###
       Return: function (eqn) -> eqn that preprocesses the user formula input before
                 it is fed into MathJax. Return 'false' if no preprocessor specified
       ###
-      data = $(element).find('.textinputdynamath_data')
+      data = $(element).find('.text-input-dynamath_data')
 
       preprocessorClassName = data.data('preprocessor')
       preprocessorClass = window[preprocessorClassName]