Add Armour rendering for Bust & Body

`/armor/bust/%username%` & `armor/body/%username%` (as well as `/armour/` for the proud Brits)

So, I have tried to be as efficient as possible in terms of reusing code, the result though is a boat load of functions which generally are used twice (normal vs with armour). Also a slight slowdown in Bust/Body generation (check the benchmarks).

Input is greatly appreciated :syringe:

Original  | With Armour
------------- | -------------
![lukehandle](https://cloud.githubusercontent.com/assets/799079/5432654/e66c125a-8435-11e4-8bbe-32f192bfa51d.png)  | ![lukehandle](https://cloud.githubusercontent.com/assets/799079/5432667/0750bcb4-8436-11e4-9d9e-ed17b18579d7.png)


And benchmarks:
Before:
````
BenchmarkGetHead          100000             16059 ns/op
BenchmarkGetHelm          100000             17937 ns/op
BenchmarkGetCube           20000             93265 ns/op
BenchmarkGetBust          100000             20945 ns/op
BenchmarkGetBody           50000             41083 ns/op
````

After:
````
BenchmarkGetHead          100000             16060 ns/op
BenchmarkGetHelm          100000             17296 ns/op
BenchmarkGetCube           20000             91631 ns/op
BenchmarkGetBust          100000             22213 ns/op
BenchmarkGetBody           50000             43874 ns/op
BenchmarkGetArmorBust     100000             23559 ns/op
BenchmarkGetArmorBody      50000             45734 ns/op
````

#121