Overhaul form control and button sizing, and some type styles

* New padding approach with separate horizontal and vertical padding
variables
* Improved sizing in large and small buttons and form controls
* Dropped the `.btn-mini` (since we have no `.input-mini` to match, and
holy fuck those were small buttons)
* Dropped the `.pagination-mini` as well because once again, to hell
with such small components
* Changed `@line-height-headings` to `@headings-line-height`
* Removed the `@headings-font-family` because it was honestly kind of
useless

less/pagination.less

@@ -56,7 +56,7 @@
 .pagination-large {
   > li > a,
   > li > span {
-    padding: @padding-large;
+    padding: @padding-large-vertical @padding-large-horizontal;
     font-size: @font-size-large;
   }
   > li:first-child > a,
@@ -69,9 +69,13 @@
   }
 }
 
-// Small and mini
-.pagination-mini,
+// Small
 .pagination-small {
+  > li > a,
+  > li > span {
+    padding: @padding-small-vertical @padding-small-horizontal;
+    font-size: @font-size-small;
+  }
   > li:first-child > a,
   > li:first-child > span {
     .border-left-radius(@border-radius-small);
@@ -81,20 +85,3 @@
     .border-right-radius(@border-radius-small);
   }
 }
-
-// Small
-.pagination-small {
-  > li > a,
-  > li > span {
-    padding: @padding-small;
-    font-size: @font-size-small;
-  }
-}
-// Mini
-.pagination-mini {
-  > li > a,
-  > li > span {
-    padding: @padding-mini;
-    font-size: @font-size-mini;
-  }
-}