Initial commit for _sass.

Props @michaelArestad @hugobeta, and @jacklenox.

* Give prefix to variable files. This avoids confusion with files of similar names like typography. It also helps with the visual recognition over what file does what.
* Set up mixins-master.
* Setting foundation for encouraging in larger projects use of more than one mixing file. This creates a master mixins file that we can then bring subs into if the project grows.
* Fixed line breaks, spacing and new lines. Props @gregrickaby.
* Nest widget select. Props @gregrickaby.
* Make variables be variables-site. Makes this the global variables folder. People can then use sub folders in sections for local only variables.
* Change content directory to be site directory.
* Remove zip. Revert `style.css` to not be auto generated version.
* Fixes rem size issue on body font.
* Fixes for differences between `_s` and `_sass`. Fixed font sizes, added in display block to classes so they compile and the theme check
passes.
* Remove text domain and clean up css.

sass/media/_galleries.scss

@@ -0,0 +1,46 @@
+.gallery {
+	margin-bottom: 1.5em;
+}
+
+.gallery-item {
+	display: inline-block;
+	text-align: center;
+	vertical-align: top;
+	width: 100%;
+}
+
+.gallery-columns-2 .gallery-item {
+	max-width: 50%;
+}
+
+.gallery-columns-3 .gallery-item {
+	max-width: 33.33%;
+}
+
+.gallery-columns-4 .gallery-item {
+	max-width: 25%;
+}
+
+.gallery-columns-5 .gallery-item {
+	max-width: 20%;
+}
+
+.gallery-columns-6 .gallery-item {
+	max-width: 16.66%;
+}
+
+.gallery-columns-7 .gallery-item {
+	max-width: 14.28%;
+}
+
+.gallery-columns-8 .gallery-item {
+	max-width: 12.5%;
+}
+
+.gallery-columns-9 .gallery-item {
+	max-width: 11.11%;
+}
+
+.gallery-caption {
+	display: block;
+}