Add the tooling to actually run a war inside of tomcat

Fixes #1

build.gradle

@@ -69,7 +69,7 @@ war {
   manifest { attributes 'Main-Class': 'WarMain' }
 
   webInf {
-    from 'vendor/gems', 'vendor/specifications', 'vendor/bin'
+    from 'vendor'
     into 'gems'
   }
 

src/main/webapp/WEB-INF/app.rb

@@ -4,7 +4,10 @@ end
 
 # Hack our GEM_HOME to make sure that the `rubygems` support can find our
 # unpacked gems in ./vendor/
-ENV['GEM_HOME'] = File.expand_path(File.dirname(__FILE__) + '/vendor')
+vendored_gems = File.expand_path(File.dirname(__FILE__) + '/vendor')
+if File.exists?(vendored_gems)
+  ENV['GEM_HOME'] = vendored_gems
+end
 
 jar_cache = File.expand_path(File.dirname(__FILE__) + '/.jarcache/')
 if File.exists?(jar_cache)

src/main/webapp/WEB-INF/config.ru

@@ -0,0 +1,5 @@
+require 'app'
+
+map '/' do
+ run Sinatra::Application
+end

src/main/webapp/WEB-INF/web.xml

@@ -0,0 +1,36 @@
+<!DOCTYPE web-app PUBLIC
+  "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
+  "http://java.sun.com/dtd/web-app_2_3.dtd">
+<web-app>
+
+  <context-param>
+    <param-name>public.root</param-name>
+    <param-value>/</param-value>
+  </context-param>
+
+  <context-param>
+    <param-name>rack.env</param-name>
+    <param-value>production</param-value>
+  </context-param>
+
+  <context-param>
+    <param-name>jruby.compat.version</param-name>
+    <param-value>1.9</param-value>
+  </context-param>
+
+
+  <filter>
+    <filter-name>RackFilter</filter-name>
+    <filter-class>org.jruby.rack.RackFilter</filter-class>
+  </filter>
+  <filter-mapping>
+    <filter-name>RackFilter</filter-name>
+    <url-pattern>/*</url-pattern>
+  </filter-mapping>
+
+  <listener>
+    <listener-class>org.jruby.rack.RackServletContextListener</listener-class>
+  </listener>
+
+
+</web-app>