Introduce src/ and dist/ folders

Separate minifying/renaming of files to prod-only tasks

Add tasks for copying jQuery and fonts

Ref #1138, #1070, #1155

assets/src/less/components/_media.less

@@ -0,0 +1,13 @@
+// Captions
+.wp-caption {
+  &:extend(.thumbnail all);
+}
+
+.wp-caption-text {
+    &:extend(.thumbnail .caption);
+}
+
+// Gallery shortcode
+.gallery-row {
+  padding: (@line-height-computed / 2) 0;
+}