Vendor GYP and libuv into the repo.

Instead of dynamically downloading these as needed during a build, this
checks in those two dependencies directly into the Wren repo. That's a
little lame because users of Wren who aren't building the CLI don't
actually need them, but they aren't too big, so it's not a huge deal.

It makes builds (particularly on Travis) more reliable, because they
don't have to pull down additional content over the network.

deps/libuv/android-configure

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+export TOOLCHAIN=$PWD/android-toolchain
+mkdir -p $TOOLCHAIN
+$1/build/tools/make-standalone-toolchain.sh \
+    --toolchain=arm-linux-androideabi-4.9 \
+    --arch=arm \
+    --install-dir=$TOOLCHAIN \
+    --platform=android-21
+export PATH=$TOOLCHAIN/bin:$PATH
+export AR=arm-linux-androideabi-ar
+export CC=arm-linux-androideabi-gcc
+export CXX=arm-linux-androideabi-g++
+export LINK=arm-linux-androideabi-g++
+export PLATFORM=android
+
+if [[ $2 == 'gyp' ]]
+  then
+    ./gyp_uv.py -Dtarget_arch=arm -DOS=android -f make-android
+fi