Adds basic icon theme, adds some more button variables

src/elements/button.less

@@ -122,7 +122,7 @@
   position: relative;
   cursor: default;
 
-  background-color: #FFFFFF !important;
+  background-color: @loadingBackgroundColor !important;
   text-shadow: none !important;
   color: transparent !important;
   transition: all 0s linear;

src/semantic.config

@@ -10,7 +10,7 @@
 @globalTheme: 'default';
 
 /* Elements */
-@button   : 'github';
+@button   : 'default';
 @icon     : 'default';
 @divider  : 'default';
 @header   : 'default';

src/themes/basic/elements/button.overrides

@@ -0,0 +1,4 @@
+/*******************************
+           Overrides
+*******************************/
+

src/themes/basic/elements/button.variables

@@ -0,0 +1,37 @@
+/*-------------------
+   Button Variables
+--------------------*/
+
+/* Button Variables */
+@textTransform: none;
+@fontWeight: normal;
+@textColor: #333333;
+
+@borderRadius: 0.25em;
+
+@backgroundColor: #E0E0E0;
+@backgroundImage: none;
+@boxShadow: none;
+
+@hoverBackgroundColor: #DDDDDD;
+@hoverBackgroundImage: none;
+@hoverBoxShadow: none;
+
+@downBackgroundColor: #D0D0D0;
+@downBackgroundImage: none;
+@downBoxShadow: none;
+
+@activeBackgroundColor: #DFDFDF;
+@activeBackgroundImage: none;
+@activeBoxShadow: none;
+
+@loadingBackgroundColor: #F0F0F0;
+
+@mini: 0.6rem;
+@tiny: 0.7rem;
+@small: 0.85rem;
+@medium: 0.92rem;
+@large: 1rem;
+@big: 1.125rem;
+@huge: 1.25rem;
+@massive: 1.3rem;

src/themes/default/elements/button.variables

@@ -53,6 +53,8 @@
 @activeBackgroundImage: none;
 @activeBoxShadow: 0px 0px 0px 1px rgba(0, 0, 0, 0.05) inset !important;
 
+@loadingBackgroundColor: #FFFFFF;
+
 @iconMargin: 0.6em;
 @iconHoverOpacity: 0.85;
 @iconButtonOpacity: 0.9;