Hi,
for the build.bat, you need to open the console window using the Visual Studio Console (or Terminal), which will run some commands to update the paths for binaries in your system. The problem there seems that CMake is not able to find the compiler.
As for the following code:
win32:CONFIG(release, debug|release): LIBS += -L$$PWD/../../../../../../fuzzylite-5.0/ -lfuzzylite
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/../../../../../../fuzzylite-5.0/ -lfuzzylited
else:unix: LIBS += -L$$PWD/../../../../../../fuzzylite-5.0/ -lfuzzylite
INCLUDEPATH += $$PWD/../../../../../../fuzzylite-5.0
DEPENDPATH += $$PWD/../../../../../../fuzzylite-5.0
The problem is that you are not finding the library. Please use the full path to fuzzylite instead of a relative ../../../ to prevent unnoticed errors. Also, some times things are funny with dynamic libraries, so you may also try using -lfuzzylite-static and -lfuzzylite-staticd instead of the dynamic versions.
Furthermore, you need to ensure that the path to fuzzylite is correct. For example, the INCLUDEPATH needs to point to the fuzzylite directory that contains folders fl and src, such that doing cd $FL_HOME/fl is a valid path to the headers. Likewise, you need to make sure that the library files are available in the fuzzylite directory or change accordingly: LIBS+=path/to/fuzzylite/release/bin/, such that the libraries are in path/to/fuzzylite/release/bin/.
Hope this helps.