Platform: improve the UX of windowless Emscripten apps.

* Wrap the text like in a console because nobody wants to read
   kilometers-long horizontal lines with a horizontal scrollbar
 * Make the output fill at least the space given to it but let it expand
   beyond because a vertical scrollbar in an area of this size is
   useless as well.

src/Magnum/Platform/WebApplication.css

@@ -112,12 +112,12 @@ body {
 #canvas, pre#log {
   max-width: 100%;
   width: 100%;
-  height: 100%;
   z-index: 10;
   border-radius: 0.2rem; /*var(--border-radius)*/
 }
 #canvas:focus { outline-color: #5b9dd9; } /*var(--header-link-current-color)*/
 #canvas {
+  height: 100%;
   margin-bottom: -0.25rem; /* otherwise there's scrollbar w/ fullsize (why?) */
 }
 #status, #status-description {
@@ -140,8 +140,12 @@ body {
   display: none;
 }
 pre#log {
+  /* Make it fill at least the space given to it but let it expand beyond
+     (scrollbars in that tiny area are useless) */
+  min-height: 100%;
   padding: 0.5rem 1rem;
-  overflow-x: auto;
+  white-space: pre-wrap; /* same as .m-console-wrap */
+  word-break: break-all;
   margin-top: 0; /* stupid defaults */
   color: #e6e6e6; /*var(--code-color)*/
   background-color: #282e36; /*var(--code-background-color)*/