Fixed permissions issue on *nix

Author: ilyalukyanov

src/LightningDB/LightningEnvironment.cs

@@ -34,6 +34,7 @@ public LightningEnvironment(string directory, EnvironmentOpenFlags openFlags, Un
             _shouldDispose = true;
 
             _handle = handle;
+            _accessMode = accessMode;
 
             this.Directory = directory;
             _openFlags = openFlags;

src/LightningDB/UnixAccessMode.cs

@@ -33,7 +33,7 @@ public enum UnixAccessMode : uint
         /// <summary>
         /// S_IXGRP
         /// </summary>
-        GroupExecute = 0x0008, 
+        GroupExec = 0x0008, 
 
         /// <summary>
         /// S_IROTH
@@ -48,7 +48,7 @@ public enum UnixAccessMode : uint
         /// <summary>
         /// S_IXOTH
         /// </summary>
-        OtherExecute = 0x0001,
+        OtherExec = 0x0001,
 
         Default = OwnerRead | OwnerWrite | GroupRead | GroupWrite | OtherRead | OtherWrite
     }