README.md, autogen.sh: encourage cmake

Especially for MSW, where GPUJPEG's autotool configuration isn't expected
to work and it is quite difficult to make it (spaces in CUDA path in
combination with libtool).

Author: MartinPulec

README.md

@@ -181,8 +181,9 @@ files are placed) and run `cmake` command:
     cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_CUDA_ARCHITECTURES=native -Bbuild .
     cmake --build build --config Release
 
-You can also use **autotools** to create a build recipe for the library and the
-application or a plain old _Makefile.bkp_. However, _cmake_ is recommended.
+In Linux, you can also use **autotools** to create a build recipe for
+the library and the application or a plain old _Makefile.bkp_. However,
+_cmake_ is recommended.
 
 Usage
 -----

autogen.sh

@@ -24,5 +24,12 @@ STATUS=$?
 
 ([ $STATUS -eq 0 ] && echo "Autogen done." ) || echo "Autogen failed."
 
+echo "Note: CMake is now preferred for GPUJPEG build configuration."
+
+if expr "$(uname -s)" : MSYS >/dev/null; then
+    printf "\nIt is highly probable that autoconf won't work in MSW - \
+use cmake if possible\n"
+fi
+
 exit $STATUS