Add support for ssh_config for connection

Signed-off-by: Anders F Björklund <anders.f.bjorklund@gmail.com>

vendor/github.com/kevinburke/ssh_config/token.go

@@ -0,0 +1,49 @@
+package ssh_config
+
+import "fmt"
+
+type token struct {
+	Position
+	typ tokenType
+	val string
+}
+
+func (t token) String() string {
+	switch t.typ {
+	case tokenEOF:
+		return "EOF"
+	}
+	return fmt.Sprintf("%q", t.val)
+}
+
+type tokenType int
+
+const (
+	eof = -(iota + 1)
+)
+
+const (
+	tokenError tokenType = iota
+	tokenEOF
+	tokenEmptyLine
+	tokenComment
+	tokenKey
+	tokenEquals
+	tokenString
+)
+
+func isSpace(r rune) bool {
+	return r == ' ' || r == '\t'
+}
+
+func isKeyStartChar(r rune) bool {
+	return !(isSpace(r) || r == '\r' || r == '\n' || r == eof)
+}
+
+// I'm not sure that this is correct
+func isKeyChar(r rune) bool {
+	// Keys start with the first character that isn't whitespace or [ and end
+	// with the last non-whitespace character before the equals sign. Keys
+	// cannot contain a # character."
+	return !(r == '\r' || r == '\n' || r == eof || r == '=')
+}