fix(table): images in tables did not display properly

This one needs a bit of explanation:
The main cause of this bug was introduced in 2014 by Semantic-Org/Semantic-UI@400949c
It was related to issue Semantic-Org/Semantic-UI#1510, where it seemed to be fixed but the main cause was the `collapsing` class set to the cell column, which causes the width to be reduced to 1px to force the browser to reduce its width until the main occupied content got the minimum width.
So, this PR actually reverts the fix for Semantic-Org/Semantic-UI#1510 and fixes the main cause correctly now.

Closes #227

src/definitions/collections/table.less

@@ -209,10 +209,8 @@
 *******************************/
 
 /* UI Image */
-.ui.table th .image,
-.ui.table th .image img,
-.ui.table td .image,
-.ui.table td .image img {
+.ui.table .collapsing .image,
+.ui.table .collapsing .image img {
   max-width: none;
 }