Fix tkremind fontchooser issues.

1. Pass -name to wish to set the window class explicitly.  Without this,
   wrap-program renames tkremind to .tkremind-real, and Tk uses the script
   basename as the window class.  A class starting with "." breaks the
   fontchooser which interprets it as a window path.

2. Fix bug in SetHeadingFont: it references Option(HeadingFont) before it
   is set, causing "can't read Option(HeadingFont): no such variable" when
   selecting a heading font.  Use the just-configured HeadingFont instead.

diff --git a/scripts/tkremind.in b/scripts/tkremind.in
--- a/scripts/tkremind.in
+++ b/scripts/tkremind.in
@@ -13,7 +13,7 @@
 #--------------------------------------------------------------

 # the next line restarts using wish \
-exec wish "$0" "$@"
+exec wish "$0" -name Tkremind "$@"

 tk appname tkremind

@@ -5190,7 +5190,7 @@ proc SetHeadingFont {font} {
     global tmpOpt
     font configure HeadingFont {*}[font actual $font]
-    font configure BoldFont {*}$Option(HeadingFont) -weight bold
+    font configure BoldFont {*}[font actual HeadingFont] -weight bold
     set tmpOpt(HeadingFont) [font actual $font]
     raise .opt
 }