I was experiencing no margin with the photos on the wordpress blogs I deal with and I saw in the theme I use (default) it exists a class alignleft (and also alignright and centered) that put margins for the photos of this class.
I decided so to adapt the selection of the alignment in the writing to write class="alignleft" instead of align="left" and same for right and centered (centered instead of absmiddle). So I add a if in function insertImage of wp-includes/js/tinymce/themes/advanced/jscripts
If it was one of the above terms it should put align=''; and class='termabove';
I also modified InsertImage(manyarguments) of wp-includes/js/tinymce/tiny_mce.js by adding class in the argument and modifying the function doing like the other arguments.
Unfortunetely it didn't work. Beside even if I force align to alignleft in wp-includes/js/tinymce/themes/advanced/image.htm or wp-includes/js/tinymce/themes/advanced/jscripts it still display align="left" in the source of the webpage.
Where am I wrong ? Could you give me just a tip ?