Add node management.
Fix not to reuse unfiltered expr for filterExprBySource

`return expr` in the last line of `filterExprBySource` can
return unfiltered results, so fixing it by reconstruction
using filtered elements.

also added a test which can cause this problem.
Change influxql default associativity from right to left.

Closes #1266

modified one testcase as it was depending on right
associativity.
Rename Node to DataNode.
Remove data node sort in the metastore.
Add DataNode autoincrementing sequence.
Reanme Shard.nodeIDs to Shard.dataNodeIDs.
Merge pull request #1272 from influxdb/nodes

Add node management
Merge pull request #1269 from blmarket/master

Fix not to reuse unfiltered expr for filterExprBySource
Merge pull request #1273 from blmarket/change-default-assoc

Change influxql default associativity from right to left.
Fix tests for /raft prefix.
Merge pull request #1274 from influxdb/raft-prefix

Fix tests for /raft prefix
Update QUERIES.md

make changes to how list tag values works.
Wiring graphite end point back up

Graphite server now understands how to use the WriteSeries

Added ability for series information to be passed in the graphite name.

Format is:

	key.value.key.value.metric 50 <timestamp>\n

Example:

	region.us-west.hostname.server01.cpu .09323432 1419958066\n

Added test coverage for the Graphite endpoint.  Need to figure out
how to test a successful listenAndServe.

Need to add tests around new configuration for default values
when not specified for graphite servers.

Changes to be committed:
modified:   cmd/influxd/config.go
modified:   cmd/influxd/config_test.go
modified:   cmd/influxd/run.go
modified:   graphite.go
new file:   graphite_test.go
Merge branch 'master' into graphite
handler_test.go should pass go vet