Move all Button CSS from theme_base.css to cs-defaults.css

[TheWebTech]

Someone previously contributed this CSS for Flat buttons. Let's move it into Crankshaft itself. (cs-defaults.css)
We likely will need to make some changes to this but lets get this moved over first.

Delete the reference to these buttons in theme_base.css that will help us know we've stripped that part out.

CrankShaft/theme/theme_base.css

Lines 1042 to 1114 in e7c5472

	/* Flat UI Buttons
	========================================================================== */
	.btn {
	border-radius: 5px;
	padding: 15px 25px;
	font-size: 22px;
	text-decoration: none;
	margin: 20px;
	color: #fff;
	position: relative;
	display: inline-block;
	}
	.btn:active {
	transform: translate(0px, 5px);
	-webkit-transform: translate(0px, 5px);
	box-shadow: 0px 1px 0px 0px;
	}
	.blue {
	background-color: #55acee;
	box-shadow: 0px 5px 0px 0px #3C93D5;
	}
	.blue:hover {
	background-color: #6FC6FF;
	}
	.green {
	background-color: #2ecc71;
	box-shadow: 0px 5px 0px 0px #15B358;
	}
	.green:hover {
	background-color: #48E68B;
	}
	.red {
	background-color: #e74c3c;
	box-shadow: 0px 5px 0px 0px #CE3323;
	}
	.red:hover {
	background-color: #FF6656;
	}
	.purple {
	background-color: #9b59b6;
	box-shadow: 0px 5px 0px 0px #82409D;
	}
	.purple:hover {
	background-color: #B573D0;
	}
	.orange {
	background-color: #e67e22;
	box-shadow: 0px 5px 0px 0px #CD6509;
	}
	.orange:hover {
	background-color: #FF983C;
	}
	.yellow {
	background-color: #f1c40f;
	box-shadow: 0px 5px 0px 0px #D8AB00;
	}
	.yellow:hover {
	background-color: #FFDE29;
	}

Kinda related to #9

and is a sub-task of #35