Qt status fix: 'showexp'

For Qt, experience points weren't shown when enabling 'showexp'
option because they were conditional upon '#if EXP_ON_BOTL'.  That
got eliminated prior to 3.6.0 so wasn't defined for qt_stat.cpp.

When displayed, show Exp as Level:Xp/Exp instead of as a separate
status field.  This has the intentional side-effect of omitting it
when hero is polymorphed and status shows HD instead of Xp.

Label the six characteristics in mixed case instead of all upper
case:  Str, Dex, and so forth.

win/Qt/qt_stat.h

@@ -78,10 +78,11 @@ private:
 	NetHackQtLabelledIcon hp;
 	NetHackQtLabelledIcon power;
 	NetHackQtLabelledIcon ac;
-	NetHackQtLabelledIcon level;
-	NetHackQtLabelledIcon exp;
-	NetHackQtLabelledIcon align;
-
+        NetHackQtLabelledIcon level; // Xp level
+        NetHackQtLabelledIcon exp;   // appended to Xp rather than separate
+                                     // but still used to pad their line
+        NetHackQtLabelledIcon align; // alignment is on Conditions line
+                                     // because it has an icon above it
 	NetHackQtLabelledIcon time;
 	NetHackQtLabelledIcon score;