Introduce developer guide

 - Port instructions for building from source from Markdown to Asciidoc
 - Make these instructions one section in a larger 'developer guide'
   document. Done for symmetry with the user guide forthcoming in #91.

docs/devguide.adoc

@@ -0,0 +1,76 @@
+Bitsquare Developer Guide
+=========================
+Chris Beams <chris@beams.io>
+:toc:
+
+Introduction
+------------
+
+TODO
+
+Build from source
+-----------------
+
+This section of the guide will walk you through the process of building Bitsquare from source.
+
+NOTE: For most users, building from source is not necessary. See the https://github.com/bitsquare/bitsquare/releases[releases page], where you'll find installers for Windows, Linux and Mac OS X.
+
+
+=== For the impatient
+
+What follows is explained in detail in the sections below, but for those who know their way around Java, git and Gradle, here are the instructions in a nutshell:
+
+    $ javac -version
+    javac 1.8.0_20       # must be 1.8.0_20 or better
+
+    $ git clone https://github.com/bitsquare/bitsquare.git
+    $ cd bitsquare
+    $ ./gradlew build    # (on *nix)
+       --- or ---
+    $ gradlew build      # (on Windows)
+
+When the build completes, you will find executables and installers specific to your platform in the `build/distributions/` directory.
+
+
+=== Prerequisites
+
+The only prerequisite for building Bitsquare is installing the Java Development Kit (JDK), version 8u20 or better.
+
+To check the version of Java you currently have installed:
+
+    $ javac -version
+    javac 1.8.0_20
+
+If `javac` is not found, or your version is anything less than `1.8.0_20`, then you'll need to http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html[download and install the latest JDK] for your platform.
+
+TIP: Here are http://www.webupd8.org/2014/03/how-to-install-oracle-java-8-in-debian.html[instructions] for installing the JDK via `apt` on Debian or Ubuntu systems.
+
+
+=== Steps
+
+==== 1. Get the source
+
+The preferred approach is to clone the Bitsquare repository using http://www.git-scm.com/[git]:
+
+    git clone https://github.com/bitsquare/bitsquare.git
+
+However, if you're not familiar with git or it is otherwise inconvenient to use, you can also download and extract a zip file of the latest sources at https://github.com/bitsquare/bitsquare/archive/master.zip.
+
+
+==== 2. Build
+
+Bitsquare uses http://www.gradle.org/[Gradle], and the http://www.gradle.org/docs/current/userguide/gradle_wrapper.html[Gradle wrapper] as a build system. This means you don't need to download or do anything other than run the following command within the `bitsquare` directory.
+
+    ./gradlew build
+
+NOTE: on Windows, leave out the `./` and simply run `gradlew build`.
+
+
+==== 3. Run
+
+When the build completes, you'll find executables and installers in the `build/distributions` directory.
+
+
+=== Troubleshooting
+
+If the instructions above don't work for you, please https://github.com/bitsquare/bitsquare/issues/new?labels=%5Bbuild%5D[raise an issue]. Thanks!