ui: Added on-demand local reference navigation to code view navigation bar (issue #453, #538)

* show local reference navigation for local symbols and multiple edge references
* shortcut Ctrl/Cmd + T
* iterate with consecutive edge clicks

bin/app/data/color_schemes/bad_rainbow.xml

@@ -184,7 +184,7 @@
 						<text>#262626</text>
 					</focus>
 					<active>
-						<border>transparent</border>
+						<border>white</border>
 						<fill>#A5DEFF</fill>
 						<text>#262626</text>
 					</active>

bin/app/data/color_schemes/bright.xml

@@ -183,7 +183,7 @@
 						<fill>#C6EAFF</fill>
 					</focus>
 					<active>
-						<border>transparent</border>
+						<border>#136391</border>
 						<fill>#C6EAFF</fill>
 					</active>
 				</local_symbol>

bin/app/data/color_schemes/dark.xml

@@ -184,7 +184,7 @@
 						<text>#191919</text>
 					</focus>
 					<active>
-						<border>transparent</border>
+						<border>white</border>
 						<fill>#969696</fill>
 						<text>#272728</text>
 					</active>

bin/app/data/gui/code_view/code_view.css

@@ -24,7 +24,7 @@
 	border: none;
 }
 
-#code_navigation * {
+#code_navigation QLabel {
 	color: <color:code/file/title/text>;
 	font-size: <setting:font_size>px;
 }
@@ -50,11 +50,39 @@
 }
 
 #code_navigation #reference_button_previous {
+	/*width: 20px;*/
+	padding-bottom: 2px;
+
 	border-bottom-left-radius: 11px;
 	border-top-left-radius: 11px;
 }
 
 #code_navigation #reference_button_next {
+	/*width: 20px;*/
+	padding-top: 3px;
+
+	border-bottom-right-radius: 11px;
+	border-top-right-radius: 11px;
+}
+
+#code_navigation #file_button_previous, #code_navigation #file_button_next {
+	width: 22px;
+}
+
+#code_navigation #file_button_previous, #code_navigation #local_reference_button_previous {
+	border-bottom-left-radius: 11px;
+	border-top-left-radius: 11px;
+}
+
+#code_navigation #local_reference_button_previous {
+	padding-bottom: 2px;
+}
+
+#code_navigation #local_reference_button_next {
+	padding-top: 3px;
+}
+
+#code_navigation #file_button_next, #code_navigation #local_reference_button_next {
 	border-bottom-right-radius: 11px;
 	border-top-right-radius: 11px;
 }