Special handling for links without href attribute

The link change overrides link colors in last modified,
talk button and main menu. This approach was obviously flawed.

Rather than enter a specificity
war let's instead limit the styles to links which do not have
an href. Volker you were right...

* Revert "Last modified links should not be progressive blue"
This reverts commit bc045b78a2.
* Revert "Do not style links without href attribute"
This reverts commit daa6ad5145.
* Apply a not selector for links

Certain links (including links inside navboxes) render
links to themselves - for example the navbox on the San
Francisco article (provided it is not removed by
wgMFRemovableClasses)

These links should be visually distinguished from normal links.
The not selector has support from IE9 onwards and given our browser
matrix and the low impact of if this fallback fails this is a perfectly
acceptable usecase.

Bug: T181472

Change-Id: I61b05e3c223f2ba5314aecdf26b8a0ee8caa6524

resources/skins.minerva.base.styles/print/footer.less

@@ -28,7 +28,7 @@
 	}
 
 	.last-modified-bar,
-	.last-modified-bar a[href] {
+	.last-modified-bar a {
 		font-weight: bold !important;
 		color: #000 !important;
 	}

resources/skins.minerva.base.styles/ui.less

@@ -46,7 +46,7 @@ body {
 	color: @colorGray5;
 	transition: background-color 0.2s ease, color 0.2s ease;
 
-	a[href],
+	a,
 	a:visited {
 		color: @colorGray5;
 		// If browser supports

resources/skins.minerva.content.styles/links.less

@@ -8,12 +8,14 @@
  * links can be differentiated from other links. Thus we only apply the linkColor to links with href
  * attributes.
 */
-a[href] {
-	color: @linkColor;
+/* stylelint-disable no-descending-specificity */
+a:not( [href] ) {
+	color: @colorGray2;
 }
 
 a {
 	text-decoration: none;
+	color: @linkColor;
 
 	&:visited {
 		color: #5a3696;