File update metadata API

README.md

@@ -307,6 +307,7 @@ file.size                 // for a directory, computes the directory size
 file.posixAttributes / file.dosAttributes  // see file.attributes
 file.isEmpty      // true if file has no content (or no children if directory) or does not exist
 file.isParentOf / file.isChildOf / file.isSiblingOf / file.siblings
+file("dos:system") = true  // set custom meta-data for file (similar to Files.setAttribute)
 ```
 All the above APIs let you specify the [`LinkOption`](http://docs.oracle.com/javase/8/docs/api/java/nio/file/LinkOption.html) either directly:
 ```scala

core/src/main/scala/better/files/File.scala

@@ -2,7 +2,7 @@ package better.files
 
 import java.io.{File => JFile, _}
 import java.net.URI
-import java.nio.channels.{OverlappingFileLockException, AsynchronousFileChannel, FileChannel, NonWritableChannelException, NonReadableChannelException}
+import java.nio.channels._
 import java.nio.file._, attribute._
 import java.security.MessageDigest
 import java.time.Instant
@@ -388,6 +388,19 @@ class File private(val path: Path) {
     algorithm.digest()
   }
 
+  /**
+    * Set a file attribute e.g. file("dos:system") = true
+    *
+    * @param attribute
+    * @param value
+    * @param linkOptions
+    * @return
+    */
+  def update(attribute: String, value: Any)(implicit linkOptions: File.LinkOptions = File.LinkOptions.default): this.type = {
+    Files.setAttribute(path, attribute, value, linkOptions : _*)
+    this
+  }
+
   /**
     * @return checksum of this file (or directory) in hex format
     */