MacOSX: Add for using FUSE-T instead of MacFUSE

The build script build_veracrypt_macosx.h now accepts the argument -f to enable fuse-t support.
It is also possible to set the environment variable VC_OSX_FUSET to 1 for FUSE-T support.
A change was done in CoreUnix::GetMountedVolumes to add a waiting loop  for control file to be accessible because when using FUSE-T there always a delay before control file can be serialized.

src/Build/build_veracrypt_macosx.sh

@@ -14,14 +14,24 @@ SOURCEPATH=$(cd "$(dirname "$SCRIPTPATH/../.")"; pwd)
 # directory where the VeraCrypt project has been checked out
 PARENTDIR=$(cd "$(dirname "$SCRIPTPATH/../../../.")"; pwd)
 
-while getopts bp flag
+while getopts bpf flag
 do
     case "${flag}" in
         b) brew=true;;
         p) package=true;;
+        f) fuset=true;;
     esac
 done
 
+export VC_OSX_FUSET=0
+
+if [ -n "$fuset" ]; then
+    echo "Building VeraCrypt with FUSE-T support"
+    VC_OSX_FUSET=1
+else
+    echo "Building VeraCrypt with MacFUSE support"
+fi
+
 if [ -n "$brew" ]; then
     export VC_OSX_SDK=$(xcrun --show-sdk-version) #use the latest version installed, this might fail
     export VC_OSX_TARGET=${VC_OSX_SDK}