Rename QT_LOWLEVEL_{HDR,SRC} to just QT_{HDR,SRC}

These file lists contained files that were not low level (meaning "used
by wxQt/Univ" in this context) at all and it doesn't make much sense to
think about Qt-based wxUniv port anyhow, so instead of painstakingly
separating them in low level part and the rest, just rename the
variables to be less confusing.

build/bakefiles/files.bkl

@@ -239,7 +239,7 @@ IMPORTANT: please read docs/tech/tn0016.txt before modifying this file!
 <!--                               wxQT                                       -->
 <!-- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -->
 
-<set var="QT_LOWLEVEL_HDR" hints="files">
+<set var="QT_HDR" hints="files">
     wx/qt/accel.h
     wx/qt/app.h
     wx/qt/apptbase.h
@@ -324,7 +324,7 @@ IMPORTANT: please read docs/tech/tn0016.txt before modifying this file!
     wx/qt/private/winevent.h
 </set>
 
-<set var="QT_LOWLEVEL_SRC" hints="files">
+<set var="QT_SRC" hints="files">
     src/qt/accel.cpp
     src/qt/app.cpp
     src/qt/apptraits.cpp
@@ -440,12 +440,6 @@ IMPORTANT: please read docs/tech/tn0016.txt before modifying this file!
     src/generic/activityindicator.cpp
 </set>
 
-<set var="QT_HDR" hints="files">
-</set>
-
-<set var="QT_SRC" hints="files">
-</set>
-
 <set var="MEDIA_QT_SRC" hints="files">
     src/qt/mediactrl.cpp
 </set>
@@ -3638,7 +3632,6 @@ IMPORTANT: please read docs/tech/tn0016.txt before modifying this file!
         <if cond="TOOLKIT=='OSX_IPHONE'">$(OSX_LOWLEVEL_SRC)</if>
         <if cond="TOOLKIT=='X11'">$(X11_LOWLEVEL_SRC)</if>
         <if cond="TOOLKIT=='DFB'">$(DFB_LOWLEVEL_SRC)</if>
-        <if cond="TOOLKIT=='QT'">$(QT_LOWLEVEL_SRC)</if>
     </set>
     <set var="LOWLEVEL_HDR" hints="files">
         <if cond="TOOLKIT=='GTK' and TOOLKIT_VERSION=='3'">$(GTK_LOWLEVEL_HDR)</if>
@@ -3650,7 +3643,6 @@ IMPORTANT: please read docs/tech/tn0016.txt before modifying this file!
         <if cond="TOOLKIT=='OSX_IPHONE'">$(OSX_LOWLEVEL_HDR)</if>
         <if cond="TOOLKIT=='X11'">$(X11_LOWLEVEL_HDR)</if>
         <if cond="TOOLKIT=='DFB'">$(DFB_LOWLEVEL_HDR)</if>
-        <if cond="TOOLKIT=='QT'">$(QT_LOWLEVEL_HDR)</if>
     </set>
 
     <set var="PLATFORM_SRC" hints="files">

build/files

@@ -186,7 +186,7 @@ BASE_OSX_NOTWXMAC_HDR =
 
 ## Qt
 
-QT_LOWLEVEL_HDR =
+QT_HDR =
     wx/qt/accel.h
     wx/qt/app.h
     wx/qt/apptbase.h
@@ -269,7 +269,7 @@ QT_LOWLEVEL_HDR =
     wx/qt/window.h
     wx/qt/private/winevent.h
 
-QT_LOWLEVEL_SRC=
+QT_SRC=
     src/qt/accel.cpp
     src/qt/app.cpp
     src/qt/apptraits.cpp