[0.9.4.1] DROP SERIES with a regex for the measurement matches every measurement

[beckettsean]

DROP SERIES FROM /regex/ doesn't throw a parser error, but it also doesn't process the regex correctly, and appears to match every series regardless of the actual regex:

First set up some trivial points:

> select * from /.*/
name: a
-------
time                value
2015-09-29T23:38:05.053831883Z  1


name: aa
--------
time                value
2015-09-29T23:38:16.5497425Z    1


name: b
-------
time                value
2015-09-29T23:38:10.365167564Z  1


name: bb
--------
time                value
2015-09-29T23:38:20.158076911Z  1


name: c
-------
time                value
2015-09-29T23:38:23.318307Z 1


name: cc
--------
time                value
2015-09-29T23:38:24.766492625Z  1

Now drop a particular series:

> drop series from aa
> select * from /aa/
> select * from /.*/
name: a
-------
time                value
2015-09-29T23:38:05.053831883Z  1


name: b
-------
time                value
2015-09-29T23:38:10.365167564Z  1


name: bb
--------
time                value
2015-09-29T23:38:20.158076911Z  1


name: c
-------
time                value
2015-09-29T23:38:23.318307Z 1


name: cc
--------
time                value
2015-09-29T23:38:24.766492625Z  1

So far so good. Now let's drop a regex set of series:

> drop series from /a/
> select * from /.*/
> show series
> 

Suddenly every point for every series is gone, even the ones that cannot match /a/.

[beckettsean]

Should be addressed at the same time as #4280

[dgnorton]

Looked at #4280 and it's unrelated.