BUG: pandas.io.sql.frame_query truncates column aliases (col names too?)
To reproduce: Connect to DB (SQL Server 2008 R2) using pyodbc (unixODBC drivers via FreeTDS, Mac OSX). SELECT blah as some_alias, call in to the DB (w/ write frame). If "some_alias" is longer than 30 characters (it looks like), the column names are truncated.

Code: Depending on the DB configuration...

``` python
>>> import pandas as pd
>>> import pyodbc as db
>>> query = """SELECT PartNumber as this_is_some_ridiculously_long_alias_that_will_be_truncated FROM clean.Parts"""
>>> conn = db.connect('DSN=PartsAutoUpdate;UID=suser;PWD=This_Is_A_Really_Secure_Passw0rd!!')
>>> df = pd.io.sql.frame_query(query, conn)
>>> df.columns
Index([u'this_is_some_ridiculously_long'], dtype='object')
```
