(LoopbackFS) Add support for case insensitive file systems

LoopbackFS detects if the backing storage supports case sensitive names
and disables the feature in case it is unsupported.

This requires FUSE for OS X 2.7.1 or newer.

filesystems-objc/LoopbackFS/LoopbackFS.m

@@ -259,6 +259,18 @@ - (NSDictionary *)attributesOfFileSystemForPath:(NSString *)path
     NSMutableDictionary* attribs = [NSMutableDictionary dictionaryWithDictionary:d];
     [attribs setObject:[NSNumber numberWithBool:YES]
                 forKey:kGMUserFileSystemVolumeSupportsExtendedDatesKey];
+
+    NSURL *URL = [NSURL fileURLWithPath:p isDirectory:YES];
+    NSNumber *supportsCaseSensitiveNames = nil;
+    [URL getResourceValue:&supportsCaseSensitiveNames
+                   forKey:NSURLVolumeSupportsCaseSensitiveNamesKey
+                        error:NULL];
+    if (supportsCaseSensitiveNames == nil) {
+      supportsCaseSensitiveNames = [NSNumber numberWithBool:YES];
+    }
+    [attribs setObject:supportsCaseSensitiveNames
+                forKey:kGMUserFileSystemVolumeSupportsCaseSensitiveNamesKey];
+
     return attribs;
   }
   return nil;