New Maven archetype - Githubissues

[Apologies to hukun for toe stepping; sometimes I can't ignore my need for 
expedience.]

Purpose of code changes on this branch:

Provide a Maven archetype via which people who desire to create a PlayN project 
can easily create a skeleton project which contains all of the necessary 
machinations for building on all four supported platforms.

The archetype is built and installed as a part of the PlayN project, which is 
how Maven intends for things to be done. Having a binary copy of the build 
results of our PlayN archetype in sample/m2 is not the right way to do it. I 
would have pointed that out earlier, except that I didn't know that until I did 
some research into Maven archetype creation so that I could create this 
archetype.

Since the archetype is built and installed as a standard PlayN artifact, when 
we eventually ship a release to Maven Central, our archetype will automatically 
get shipped along with the release and be available to everyone in the world to 
use. Yay!

This archetype creates all four subproject types: core/java, html, flash and 
android. It asks the creator for a gameName (e.g. Foozle) which is used for 
class and file names everywhere (e.g. Foozle.html, Foozle.gwt.html, FoozleJava, 
FoozleFlash, etc.).

I took the liberty of following standard Maven project guidelines instead of 
using PlayN's idiosyncratic structure. This means source code goes in 
src/main/java/${package} instead of src/${package}, and the webapp stuff goes 
in src/main/webapp instead of war. That latter one was a GWT-ism that can now 
be worked around.

I will create a wiki page explaining how to use this archetype from the command 
line and from Maven, and giving guidance on the questions it asks prior project 
setup.

When reviewing my code changes, please focus on:
https://github.com/threerings/playn/commit/6e85b834d1b9ff91b1d4dbc22c1c39929ed3d
38f

Quick instructions for testing this archetype:

% cd playn
[if you haven't already]
% git remote add samskivert git://github.com/threerings/playn.git
[/if you haven't already]
% git fetch samskivert
% git checkout -b samskivert-archetype
% git cherry-pick 6e85b834d1b9ff91b1d4dbc22c1c39929ed3d38f
% cd archetype
% mvn install
% cd /tmp [or somewhere you can create a scratch project]
% mvn archetype:generate
[blah blah blah]
440: local -> playn-archetype (Archetype for PlayN game projects.)
Choose a number: XXX: [enter 440 or whatever your playn-archetype is]
[fill in the blanks as requested, remember gameName should be ClassNameFormat, 
for example]
Define value for property 'groupId': : com.samskivert
Define value for property 'artifactId': : monkeys
Define value for property 'version':  1.0-SNAPSHOT: : 
Define value for property 'package':  com.samskivert: : com.samskivert.monkeys
Define value for property 'gameName': : Monkeys

Then import the resulting project into Eclipse or test it from the command 
line, as you prefer.

After the review, I'll merge this branch into:
/trunk
Original issue reported on code.google.com by samskiv...@gmail.com on 25 Aug 2011 at 10:49
Merged into: #31
fredsa / playn

New Maven archetype #32
