"Media object" applies margin to any `pull-left|right` children

Created by: necolas

This code:

.media .pull-left {
  margin-right: 10px;
}
.media .pull-right {
  margin-left: 10px;
}

…will apply those margins to any element using the pull-left or pull-right class within media. This code is not specific enough to limit the styles to media image positioning alone. It causes problems when you have more complicated components within the body of a "media object".