add modal variables and tweak padding for min-height on modal title

docs/assets/css/bootstrap.css

@@ -4302,18 +4302,18 @@ button.close {
 }
 
 .modal-header {
-  min-height: 40px;
-  padding: 9px 15px;
+  min-height: 35px;
+  padding: 15px;
   border-bottom: 1px solid #e5e5e5;
 }
 
 .modal-header .close {
-  margin-top: 2px;
+  margin-top: -2px;
 }
 
 .modal-title {
   margin: 0;
-  line-height: 30px;
+  line-height: 20px;
 }
 
 .modal-body {

less/modals.less

@@ -74,19 +74,19 @@
 // Modal header
 // Top section of the modal w/ title and dismiss
 .modal-header {
-  padding: 9px 15px;
+  padding: @modal-title-padding;
   border-bottom: 1px solid #e5e5e5;
-  min-height:40px;
+  min-height: (@modal-title-padding + @modal-title-line-height);
 }
 // Close icon
 .modal-header .close {
-  margin-top: 2px;
+  margin-top: -2px;
 }
 
 // Title text within header
 .modal-title {
   margin: 0;
-  line-height: 30px; // effectively set a min-height for the header
+  line-height: @modal-title-line-height;
 }
 
 // Modal body

less/variables.less

@@ -274,6 +274,9 @@
 // -------------------------
 @modal-inner-padding:         20px;
 
+@modal-title-padding:         15px;
+@modal-title-line-height:     @line-height-base;
+
 
 // Progress bars
 // -------------------------