Ensure 16-bit input images embed onto alpha background

Support gamma correction of images with alpha channel
Favour shrink over affine when reducing by integral factor

package.json

@@ -47,11 +47,11 @@
     "vips"
   ],
   "dependencies": {
-    "bluebird": "^3.1.1",
+    "bluebird": "^3.1.5",
     "color": "^0.11.1",
     "nan": "^2.2.0",
     "semver": "^5.1.0",
-    "request": "^2.67.0",
+    "request": "^2.69.0",
     "tar": "^2.2.1"
   },
   "devDependencies": {
@@ -60,10 +60,10 @@
     "exif-reader": "^1.0.0",
     "icc": "^0.0.2",
     "istanbul": "^0.4.2",
-    "mocha": "^2.3.4",
-    "mocha-jshint": "^2.2.6",
+    "mocha": "^2.4.5",
+    "mocha-jshint": "^2.3.0",
     "node-cpplint": "^0.4.0",
-    "rimraf": "^2.5.0",
+    "rimraf": "^2.5.1",
     "bufferutil": "^1.2.1"
   },
   "license": "Apache-2.0",