cleanup of batch files

build.bat

@@ -1,20 +1,20 @@
 @echo off
 
 echo Saving PATH
-set OLDPATH=%PATH%
+if "%OLDPATH%"=="" set OLDPATH=%PATH%
 
 if "%1%"=="x32" (
-    call setenv_x32.bat
+    call setenv.bat x32
     set type="Win32"
 ) else if "%1%"=="x64" (
-    call setenv_x64.bat
+    call setenv.bat x64
     set type="x64"
 ) else if "%1%"=="coverity" (
     if "%2"=="" (
         echo "usage: build.bat coverity x32/x64"
         goto :eof
     )
-    call setenv_coverity.bat
+    call setenv.bat coverity
     echo Building with Coverity
     cov-configure --msvc
     cov-build --dir cov-int --instrument build.bat %2%
@@ -48,4 +48,5 @@ cd ..
 cd ..
 
 echo Resetting PATH
-set PATH=%OLDPATH%
+set PATH=%OLDPATH%
+set OLDPATH=

build_coverity.bat

@@ -1,5 +0,0 @@
-@echo off
-cov-configure --msvc
-cov-build --dir cov-int --instrument build_x64.bat
-
-exit

setenv.bat

@@ -0,0 +1,42 @@
+@echo off
+
+if "%OLDPATH%"=="" set OLDPATH=%PATH%
+
+if "%1%"=="x32" (
+    goto x32
+) else if "%1%"=="x64" (
+    goto x64
+) else if "%1%"=="coverity" (
+    goto coverity
+) else if "%1%"=="doxygen" (
+    goto doxygen
+) else (
+    echo "usage: setenv x32/x64/coverity/doxygen"
+    goto :eof
+)
+
+:x32
+echo Setting Qt in PATH
+set PATH=%PATH%;"c:\Qt\qt-4.8.6-x86-msvc2013\qt-4.8.6-x86-msvc2013\bin"
+set PATH=%PATH%;"c:\Qt\qtcreator-3.1.1\bin"
+echo Setting VS in PATH
+call "c:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\vcvarsall.bat"
+goto :eof
+
+:x64
+echo Setting Qt in PATH
+set PATH=%PATH%;"c:\Qt\qt-4.8.6-x64-msvc2013\qt-4.8.6-x64-msvc2013\bin"
+set PATH=%PATH%;"c:\Qt\qtcreator-3.1.1\bin"
+echo Setting VS in PATH
+call "c:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\vcvarsall.bat" amd64
+goto :eof
+
+:coverity
+echo Setting Coverity in PATH
+set PATH=%PATH%;"c:\coverity\bin"
+goto :eof
+
+:doxygen
+echo Setting Doxygen in PATH
+set PATH=%PATH%;"C:\Program Files\doxygen\bin"
+goto :eof

setenv_coverity.bat

@@ -1,3 +0,0 @@
-@echo off
-echo Setting Coverity in PATH
-set PATH=%PATH%;"c:\coverity\bin"

setenv_doxygen.bat

@@ -1,3 +0,0 @@
-@echo off
-echo Setting Doxygen in PATH
-set PATH=%PATH%;"C:\Program Files\doxygen\bin"

setenv_x32.bat

@@ -1,6 +0,0 @@
-@echo off
-echo Setting Qt in PATH
-set PATH=%PATH%;"c:\Qt\qt-4.8.6-x86-msvc2013\qt-4.8.6-x86-msvc2013\bin"
-set PATH=%PATH%;"c:\Qt\qtcreator-3.1.1\bin"
-echo Setting VS in PATH
-call "c:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\vcvarsall.bat"

setenv_x64.bat

@@ -1,6 +0,0 @@
-@echo off
-echo Setting Qt in PATH
-set PATH=%PATH%;"c:\Qt\qt-4.8.6-x64-msvc2013\qt-4.8.6-x64-msvc2013\bin"
-set PATH=%PATH%;"c:\Qt\qtcreator-3.1.1\bin"
-echo Setting VS in PATH
-call "c:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\vcvarsall.bat" amd64