Fix the build

src/main/scala/com/electronwill/niol/io/ChannelInput.scala

@@ -20,14 +20,22 @@ final class ChannelInput(private[this] val channel: ScatteringByteChannel,
 						 bufferProvider: BufferProvider = BufferProvider.DefaultOffHeapProvider)
 	extends NiolInput with Closeable {
 
-	def this(fc: FileChannel, bufferProvider: BufferProvider = BufferProvider.DefaultOffHeapProvider) = {
+	def this(fc: FileChannel, bufferProvider: BufferProvider) = {
 		this(fc, Math.min(4096, fc.size.toInt), bufferProvider)
 	}
 
-	def this(path: Path, bufferProvider: BufferProvider = BufferProvider.DefaultOffHeapProvider) = {
+	def this(fc: FileChannel) = {
+		this(fc, BufferProvider.DefaultOffHeapProvider)
+	}
+
+	def this(path: Path, bufferProvider: BufferProvider) = {
 		this(FileChannel.open(path, StandardOpenOption.READ), bufferProvider)
 	}
 
+	def this(path: Path) = {
+		this(path, BufferProvider.DefaultOffHeapProvider)
+	}
+
 	private[this] val buffer: NiolBuffer = {
 		new CircularBuffer(bufferProvider.getBuffer(bufferCapacity))
 	}

src/main/scala/com/electronwill/niol/io/ChannelOutput.scala

@@ -17,11 +17,19 @@ final class ChannelOutput(private[this] val channel: GatheringByteChannel,
 						  bufferCapacity: Int = 4096,
 						  directBuffer: Boolean = true) extends NiolOutput with Closeable {
 
-	def this(path: Path, bufferCapacity: Int = 4096, directBuffer: Boolean = true) = {
+	def this(path: Path, bufferCapacity: Int, directBuffer: Boolean) = {
 		this(FileChannel.open(path, StandardOpenOption.WRITE, StandardOpenOption.CREATE),
 			bufferCapacity, directBuffer)
 	}
 
+	def this(path: Path, bufferCapacity: Int) = {
+		this(path, bufferCapacity, true)
+	}
+
+	def this(path: Path) = {
+		this(path, 4096, true)
+	}
+
 	private[this] val buffer: ByteBuffer = {
 		if (directBuffer) {
 			ByteBuffer.allocateDirect(bufferCapacity)