Rollup merge of rust-lang#25697 - geofft:configure-friendliness, r=brson

Make the error message about missing dependencies clearer, since "need program file" is pretty confusing, and make full commands get logged, since that seems to have been the intention.

Author: Oliver Schneider

configure

@@ -1,7 +1,7 @@
 #!/bin/sh
 
 msg() {
-    echo "configure: $1"
+    echo "configure: $*"
 }
 
 step_msg() {
@@ -33,8 +33,8 @@ need_ok() {
 
 need_cmd() {
     if command -v $1 >/dev/null 2>&1
-    then msg "found program $1"
-    else err "need program $1"
+    then msg "found program '$1'"
+    else err "program '$1' is missing, please install it"
     fi
 }