travis: scripts: try to fix mingw and osx build

scripts/build_mingw_engine.sh

@@ -3,13 +3,12 @@
 # Build engine
 
 cd $TRAVIS_BUILD_DIR
-mkdir -p mingw-build && cd mingw-build
 export CC="ccache i686-w64-mingw32-gcc"
 export CXX="ccache i686-w64-mingw32-g++"
 export CFLAGS="-static-libgcc -no-pthread"
 export CXXFLAGS="-static-libgcc -static-libstdc++"
-./waf configure --sdl2=$TRAVIS_BUILD_DIR/SDL2_mingw --no-vgui --build-type=debug # can't use VGUI on MinGW
-./waf build -j2
+./waf configure -o build-mingw --sdl2=$TRAVIS_BUILD_DIR/SDL2_mingw/i686-w64-mingw32/ --no-vgui --build-type=debug # can't compile VGUI support on MinGW, due to differnet C++ ABI
+./waf build -o build-mingw -j2
 # cp SDL2/SDL2-2.0.7/i686-w64-mingw32/bin/SDL2.dll . # Install SDL2
 # cp /usr/i686-w64-mingw32/lib/libwinpthread-1.dll . # a1ba: remove when travis will be updated to xenial
 # 7z a -t7z $TRAVIS_BUILD_DIR/xash3d-mingw.7z -m0=lzma2 -mx=9 -mfb=64 -md=32m -ms=on xash_sdl.exe menu.dll SDL2.dll vgui_support.dll libwinpthread-1.dll

scripts/build_osx_engine.sh

@@ -6,8 +6,8 @@ cd $TRAVIS_BUILD_DIR
 mkdir -p osx-build && cd osx-build
 export CFLAGS="-m32"
 export CXXFLAGS="-m32"
-./waf configure --sdl2=~/Library/Frameworks/SDL2.framework/ --vgui=$TRAVIS_BUILD_DIR/vgui-dev --build-type=debug
-./waf build -j2
+python waf configure --sdl2=~/Library/Frameworks/SDL2.framework/ --vgui=$TRAVIS_BUILD_DIR/vgui-dev --build-type=debug
+python waf build -j2
 # mkdir -p pkg/
 # cp engine/libxash.dylib game_launch/xash3d mainui/libxashmenu.dylib vgui_support/libvgui_support.dylib VGUI/vgui-dev-master/lib/vgui.dylib ../scripts/xash3d.sh # pkg/
 # cp ~/Library/Frameworks/SDL2.framework/SDL2 pkg/libSDL2.dylib