V8 for couchdb.

Tested on x86/OSX, but should be fine on Linux too.

PREREQUISITES:
* V8 dinamic libraries should be installed in a place that will be found by "-lv8"

BUILD/INSTALL:
* make
* Put the resulting binary (couchv8) in a directory of your choice
* Change you couchdb config by replacing your query_servers line with this: javascript=/path/to/couchv8 /usr/local/share/couchdb/server/main.js
* Restart couchdb