More Doxygen tweaks

Seeing "Run's" in every MThread's run() description made me want to fix that
typo.  While there, made more briefs explicit, and added some

mythtv/docs/doxygen-create-developer-docs.cfg

@@ -137,7 +137,7 @@ SHORT_NAMES            = NO
 # comments will behave just like regular Qt-style comments
 # (thus requiring an explicit @brief command for a brief description.)
 
-JAVADOC_AUTOBRIEF      = YES
+JAVADOC_AUTOBRIEF      = NO
 
 # If the QT_AUTOBRIEF tag is set to YES then Doxygen will
 # interpret the first line (until the first dot) of a Qt-style