IO/SAS (sas7bdat) deleted observations are not filtered out
#### Problem description

I filled a table, then deleted two observations (rows).
![image](https://cloud.githubusercontent.com/assets/53390/24854686/08e4f466-1de8-11e7-92b1-f47fb2e37acf.png)
[datetime.sas7bdat](https://yadi.sk/d/h1En7L9M3GpDCV)
Pandas reads 5 rows with `read_sas`:
```
       Date1      Date2            DateTime                 DateTimeHi  \
0 1960-01-06 1960-01-04 1677-09-21 00:12:44 1677-09-21 00:12:43.145226   
1 1960-01-03 1960-01-05 2262-04-11 23:47:16 1960-01-01 00:00:00.000000   
2        NaT        NaT                 NaT                        NaT   
3 1960-01-06 1960-01-04 1677-09-21 00:12:44 2262-04-11 23:47:16.854774   
4 1960-01-01 1960-01-01                 NaT 1960-01-01 00:00:00.000000   

        Taiw  
0 1912-01-01  
1 1960-01-02  
2        NaT  
3 1912-01-01  
4 1960-01-01  
```


#### Expected Output

DataFrame with 3 rows instead of 5 rows (w/o index no.2 and no.4)

#### Output of ``pd.show_versions()``
last commit is cd24fa9 (ENH: add origin to to_datetime)
<details>
INSTALLED VERSIONS
------------------
commit: None
python: 3.5.3.final.0
python-bits: 64
OS: Windows
OS-release: 7
machine: AMD64
processor: Intel64 Family 6 Model 58 Stepping 9, GenuineIntel
byteorder: little
LC_ALL: None
LANG: en
LOCALE: None.None

pandas: 0+unknown
pytest: 3.0.6
pip: 9.0.1
setuptools: 34.3.2
Cython: 0.25.2
numpy: 1.11.3
scipy: 0.19.0
xarray: 0.9.1
IPython: 5.3.0
sphinx: 1.5.2
patsy: 0.4.1
dateutil: 2.6.0
pytz: 2016.10
blosc: 1.5.0
bottleneck: 1.2.0
tables: 3.3.0
numexpr: 2.6.2
feather: None
matplotlib: 2.0.0
openpyxl: None
xlrd: 1.0.0
xlwt: None
xlsxwriter: 0.9.5
lxml: 3.7.3
bs4: 4.5.3
html5lib: 1.0b10
sqlalchemy: 1.1.6
pymysql: None
psycopg2: None
jinja2: 2.9.5
s3fs: 0.0.9
pandas_gbq: None
pandas_datareader: None
</details>
