more uniform Isabelle splash screen -- avoid problems with jEdit splash and Java 11 on some Linux window managers;

--- a/Admin/MacOS/Info.plist	Tue Apr 30 17:03:32 2019 +0100
+++ b/Admin/MacOS/Info.plist	Tue Apr 30 20:54:07 2019 +0200
@@ -58,6 +58,7 @@
 <key>JVMOptions</key>
 <array>
 {JAVA_OPTIONS}
+<string>-splash:$APP_ROOT/Contents/Resources/{ISABELLE_NAME}/lib/logo/isabelle.gif</string>
 <string>-Dapple.awt.application.name={ISABELLE_NAME}</string>
 <string>-Disabelle.root=$APP_ROOT/Contents/Resources/{ISABELLE_NAME}</string>
 <string>-Disabelle.app=true</string>

--- a/Admin/Windows/launch4j/isabelle.xml	Tue Apr 30 17:03:32 2019 +0100
+++ b/Admin/Windows/launch4j/isabelle.xml	Tue Apr 30 20:54:07 2019 +0200
@@ -30,7 +30,7 @@
     <maxVersion></maxVersion>
     <jdkPreference>jdkOnly</jdkPreference>
     <runtimeBits>64</runtimeBits>
-    <opt>-Disabelle.root=&quot;%EXEDIR%&quot; -Dcygwin.root=&quot;%EXEDIR%\contrib\cygwin&quot;</opt>
+    <opt>-splash:&quot;%EXEDIR%\lib\logo\isabelle.gif&quot; -Disabelle.root=&quot;%EXEDIR%&quot; -Dcygwin.root=&quot;%EXEDIR%\contrib\cygwin&quot;</opt>
   </jre>
   <splash>
     <file>{SPLASH}</file>

--- a/src/Tools/jEdit/etc/settings	Tue Apr 30 17:03:32 2019 +0100
+++ b/src/Tools/jEdit/etc/settings	Tue Apr 30 20:54:07 2019 +0200
@@ -3,7 +3,7 @@
 JEDIT_HOME="$COMPONENT"
 JEDIT_SETTINGS="$ISABELLE_HOME_USER/jedit"
 
-JEDIT_OPTIONS="-reuseview -nobackground -log=9"
+JEDIT_OPTIONS="-reuseview -nobackground -nosplash -log=9"
 
 JEDIT_JAVA_OPTIONS="-Xms512m -Xmx2560m -Xss8m"
 JEDIT_JAVA_SYSTEM_OPTIONS="-Duser.language=en -Dawt.useSystemAAFontSettings=on -Dswing.aatext=true -Dapple.laf.useScreenMenuBar=true -Dapple.awt.application.name=Isabelle"

--- a/src/Tools/jEdit/lib/Tools/jedit	Tue Apr 30 17:03:32 2019 +0100
+++ b/src/Tools/jEdit/lib/Tools/jedit	Tue Apr 30 20:54:07 2019 +0200
@@ -433,5 +433,6 @@
     JEDIT_LOGIC_FOCUS JEDIT_INCLUDE_SESSIONS JEDIT_PRINT_MODE JEDIT_NO_BUILD JEDIT_BUILD_MODE
   export JEDIT_ML_PROCESS_POLICY="$ML_PROCESS_POLICY"
   classpath "$JEDIT_HOME/dist/jedit.jar"
-  exec isabelle java "${JAVA_ARGS[@]}" isabelle.Main "${ARGS[@]}"
+  exec isabelle java -splash:"$(platform_path "$ISABELLE_HOME/lib/logo/isabelle.gif")" \
+    "${JAVA_ARGS[@]}" isabelle.Main "${ARGS[@]}"
 fi