Fix #359 - Introduce build system based on Gulp

- Add Gulp and new dependencies to `package.json`
- Add `gulpfile.js` with four tasks:
    - `tsc`: For building TypeScript sources
    - `bundle`: For bundling JavaScript modules in a monolith
    - `sorcery`: For resolving the source map chains back to the original TypeScript files
    - `build` (`default`): Runs the whole `tsc` → `bundle` → `sorcery` chain
- Clean up `Dockerfile`, since `cpio` is not needed any more
- Clean up not needed dependencies from `package.json`
- Remove `bin/build`
- Update `bin/release` to use `npm run build` instead of `./bin/build`

Dockerfile

@@ -1,11 +1,6 @@
 FROM node:6.9
 MAINTAINER Paris Kasidiaris <paris@sourcelair.com>
 
-# Install cpio, used for building
-RUN apt-get update \
-    && apt-get install -y --no-install-recommends cpio \
-    && rm -rf /var/lib/apt/lists/*
-
 # Set the working directory
 WORKDIR /usr/src/app