Remove the word middleware (#1067)

* Rename middleware to plugin

first pass; mostly used 'sed', few spots where I manually changed
text.

This still builds a coredns binary.

* fmt error

* Rename AddMiddleware to AddPlugin

* Readd AddMiddleware to remain backwards compat

1 files changed, 0 insertions, 62 deletions

diff --git a/middleware/file/tree/print.go b/middleware/file/tree/print.go
deleted file mode 100644
index bd86ef690..000000000
--- a/middleware/file/tree/print.go
+++ /dev/null
@@ -1,62 +0,0 @@
-package tree
-
-import "fmt"
-
-// Print prints a Tree. Main use is to aid in debugging.
-func (t *Tree) Print() {
-	if t.Root == nil {
-		fmt.Println("<nil>")
-	}
-	t.Root.print()
-}
-
-func (n *Node) print() {
-	q := newQueue()
-	q.push(n)
-
-	nodesInCurrentLevel := 1
-	nodesInNextLevel := 0
-
-	for !q.empty() {
-		do := q.pop()
-		nodesInCurrentLevel--
-
-		if do != nil {
-			fmt.Print(do.Elem.Name(), " ")
-			q.push(do.Left)
-			q.push(do.Right)
-			nodesInNextLevel += 2
-		}
-		if nodesInCurrentLevel == 0 {
-			fmt.Println()
-		}
-		nodesInCurrentLevel = nodesInNextLevel
-		nodesInNextLevel = 0
-	}
-	fmt.Println()
-}
-
-type queue []*Node
-
-// newQueue returns a new queue.
-func newQueue() queue {
-	q := queue([]*Node{})
-	return q
-}
-
-// push pushes n to the end of the queue.
-func (q *queue) push(n *Node) {
-	*q = append(*q, n)
-}
-
-// pop pops the first element off the queue.
-func (q *queue) pop() *Node {
-	n := (*q)[0]
-	*q = (*q)[1:]
-	return n
-}
-
-// empty returns true when the queue contains zero nodes.
-func (q *queue) empty() bool {
-	return len(*q) == 0
-}