Reorganize CSS files to allow overrides by the user

We want to allow the user to override CSS styles with the custom.css
files. Any directive that follows the custom.css import cannot be
overridden. And because import directives must be at the start of the
file, we cannot move the import to the end of the file.

name.abuchen.portfolio.ui/css/dark_linux.css

@@ -3,6 +3,6 @@
 
 @import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/dark.css");
 
-@import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/linux.css");
+@import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/linux/linux.css");
 
 @import url("platform:/meta/name.abuchen.portfolio.ui/custom.css");

name.abuchen.portfolio.ui/css/dark_mac.css

@@ -3,17 +3,8 @@
 
 @import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/dark.css");
 
-@import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/mac.css");
+@import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/mac/mac.css");
 
-@import url("platform:/meta/name.abuchen.portfolio.ui/custom.css");
-
-/*
-Hide lines in macOS dark mode because SWT table and trees flash white
-when dragging columns and/or expanding/collapsing nodes.
+@import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/mac/dark.css");
 
-See https://github.com/eclipse-platform/eclipse.platform.swt/issues/273
-*/
-Table,
-Tree {
-	swt-lines-visible: false;
-}
+@import url("platform:/meta/name.abuchen.portfolio.ui/custom.css");

name.abuchen.portfolio.ui/css/dark_win.css

@@ -3,11 +3,8 @@
 
 @import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/dark.css");
 
-@import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/win.css");
+@import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/win/win.css");
 
-@import url("platform:/meta/name.abuchen.portfolio.ui/custom.css");
+@import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/win/dark.css");
 
-Table,
-Tree {
-	swt-lines-visible: false;
-}
+@import url("platform:/meta/name.abuchen.portfolio.ui/custom.css");

name.abuchen.portfolio.ui/css/light_linux.css

@@ -3,6 +3,6 @@
 
 @import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/light.css");
 
-@import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/linux.css");
+@import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/linux/linux.css");
 
 @import url("platform:/meta/name.abuchen.portfolio.ui/custom.css");

name.abuchen.portfolio.ui/css/light_mac.css

@@ -3,10 +3,8 @@
 
 @import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/light.css");
 
-@import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/mac.css");
+@import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/mac/mac.css");
 
-@import url("platform:/meta/name.abuchen.portfolio.ui/custom.css");
+@import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/mac/light.css");
 
-CTabFolder {
-	swt-selected-tab-fill: '#org-eclipse-ui-workbench-ACTIVE_TAB_BG_END';
-}
+@import url("platform:/meta/name.abuchen.portfolio.ui/custom.css");

name.abuchen.portfolio.ui/css/light_win.css

@@ -3,6 +3,6 @@
 
 @import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/light.css");
 
-@import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/win.css");
+@import url("platform:/plugin/name.abuchen.portfolio.ui/css/shared/win/win.css");
 
 @import url("platform:/meta/name.abuchen.portfolio.ui/custom.css");

name.abuchen.portfolio.ui/css/shared/mac/dark.css

@@ -0,0 +1,10 @@
+/*
+Hide lines in macOS dark mode because SWT table and trees flash white
+when dragging columns and/or expanding/collapsing nodes.
+
+See https://github.com/eclipse-platform/eclipse.platform.swt/issues/273
+*/
+Table,
+Tree {
+	swt-lines-visible: false;
+}

name.abuchen.portfolio.ui/css/shared/mac/light.css

@@ -0,0 +1,3 @@
+CTabFolder {
+	swt-selected-tab-fill: '#org-eclipse-ui-workbench-ACTIVE_TAB_BG_END';
+}

name.abuchen.portfolio.ui/css/shared/win/dark.css

@@ -0,0 +1,4 @@
+Table,
+Tree {
+	swt-lines-visible: false;
+}