FromClause.GetString() shouldn't assume 2 series in the merge

Fix #1047
Make sure the query string has valid regex and add a test
add some docs
Rename MergeFun to MergeRegex
Support merge with a list of series names
add a test to make sure merge cannot be used with multiple regexes
Don't include the admin assets in the distributed packages
Fix #988: top/bottom error messages
Make the error message clear when a series is missing

Fix #778
Merge pull request #1047 from influxdb/fix-1047

Allow merge() to work with one series and to take a list of time series
Merge pull request #1048 from influxdb/fix-1048

Remove the admin assets from the package
Merge pull request #1049 from influxdb/fix-988

Fix #988: top/bottom error messages
Merge pull request #778 from influxdb/issue-778

misleading error trying to select from non-existent series
Fix collectd typo in CHANGELOG
Merge pull request #1052 from tomlanyon/patch-1

Fix collectd typo in CHANGELOG
update the changelog
get the latest dependencies when we run clean
redirect output to a configurable file
Merge pull request #1021 from influxdb/fix-1021

critical errors don't hit stderr
Delete shards only after making sure no has a reference to it.

* shard_datastore.go(Deleteshard): Check the reference count of the
  shard and mark it for deletion if there are still more references out
  there. Otherwise, delete the shard immediately. Also refactor the
  deletion code in deleteShard(), see below.
* shard_datastore.go(ReturnShard): Check to see if the shard is marked
  for deletion.
* shard_datastore.go(deleteShard): Refactor the code that used to be in
  Deleteshard in its own method. Use `closeShard` instead of doing the
  cleanup ourselves.