Changed temporary buffers to a pooled bytes.Buffer implementation.

[elithrar]

I've changed bytes.NewBuffer to a pooled bytes.Buffer implementation.

This reduces garbage per-request and increases performance. Some local testing (across both Martini and a non-Martini application) saw a ~26% improvement in req/s (26k -> 33k) when making this change, and less allocations when profiled (reducing the calls to makeSlice). I've also tested a fixed (10K) buffer which sat in-between, but was less flexible as it heavily depends on the typical response size of the application.

• Pooled buffers reduce garbage per-request (render)
• Set default size as 64 as testing shows minimal memory impact and good performance (no noticeable gains above 64 buffers) - this could be exposed in render.Options if desired.
• Buffer returned to pool after writing rendered template to ResponseWriter.

(I wrote a short article on this—scroll down to the last example for how I implemented it in my own application).

[codegangsta]

I love this! Thanks @elithrar!

[codegangsta]

I will pull this down and merge it

[codegangsta]

merged