Add multiple remote sensors

Hi,

Would you consider merging in remote sensors support?
It was tested with two remote sensors pushing temperature data with http GET call.
There is a bit more info in README.md file.

Thanks.

Log screenshot with two remote sensors:
![tworemotesensors](https://f.cloud.github.com/assets/283771/1830275/a74a3806-7331-11e3-9427-ea7cafff8d0d.png)

Log screenshot with default data (after running ./build_example_database.sh)
![defaultdbplot](https://f.cloud.github.com/assets/283771/1830279/5bb33004-7332-11e3-9703-c7cddebbc48e.png)