Don't print 'unbuild' on install

Confusing to say 'this is being deleted' when that's the thing that
you're actually PUTTING there.  Only print the unbuilt pkg when it's
an explicit uninstall/unbuild command.

lib/cache.js

@@ -1173,7 +1173,7 @@ function unpack (pkg, ver, unpackTarget, dMode, fMode, uid, gid, cb) {
       log.error("unpack", "Could not read data for %s", pkg + "@" + ver)
       return cb(er)
     }
-    npm.commands.unbuild([unpackTarget], function (er) {
+    npm.commands.unbuild([unpackTarget], true, function (er) {
       if (er) return cb(er)
       tar.unpack( path.join(npm.cache, pkg, ver, "package.tgz")
                 , unpackTarget

lib/install.js

@@ -982,7 +982,7 @@ function write (target, targetFolder, context, cb_) {
     if (!er) return cb_(er, data)
 
     if (false === npm.config.get("rollback")) return cb_(er)
-    npm.commands.unbuild([targetFolder], function (er2) {
+    npm.commands.unbuild([targetFolder], true, function (er2) {
       if (er2) log.error("error rolling back", target._id, er2)
       return cb_(er, data)
     })

lib/unbuild.js

@@ -15,9 +15,12 @@ var readJson = require("read-package-json")
 
 // args is a list of folders.
 // remove any bins/etc, and then delete the folder.
-function unbuild (args, cb) { asyncMap(args, unbuild_, cb) }
+function unbuild (args, silent, cb) {
+  if (typeof silent === 'function') cb = silent, silent = false
+  asyncMap(args, unbuild_(silent), cb)
+}
 
-function unbuild_ (folder, cb) {
+function unbuild_ (silent) { return function (folder, cb) {
   folder = path.resolve(folder)
   delete build._didBuild[folder]
   log.info(folder, "unbuild")
@@ -28,12 +31,16 @@ function unbuild_ (folder, cb) {
     chain
       ( [ [lifecycle, pkg, "preuninstall", folder, false, true]
         , [lifecycle, pkg, "uninstall", folder, false, true]
+        , !silent && function(cb) {
+            console.log("unbuild " + pkg._id)
+            cb()
+          }
         , [rmStuff, pkg, folder]
         , [lifecycle, pkg, "postuninstall", folder, false, true]
         , [rm, folder] ]
       , cb )
   })
-}
+}}
 
 function rmStuff (pkg, folder, cb) {
   // if it's global, and folder is in {prefix}/node_modules,
@@ -46,7 +53,6 @@ function rmStuff (pkg, folder, cb) {
   readJson.cache.del(path.resolve(folder, "package.json"))
 
   log.verbose([top, gnm, parent], "unbuild " + pkg._id)
-  console.log("unbuild " + pkg._id)
   asyncMap([rmBins, rmMans], function (fn, cb) {
     fn(pkg, folder, parent, top, cb)
   }, cb)