Join result takes the index order of the other (right) DataFrame instead of the calling's (left) one
#### Code Sample, a copy-pastable example if possible

```python
# Your code here
df1 = pd.DataFrame({'a': [0, 10, 20]})
df2 = pd.DataFrame({'b': [200, 100]}, index=[2,1])

print(df1.join(df2, how='inner'))
print(df2.join(df1, how='inner'))

print(df1.join(df2, how='inner', sort=True))
```
#### Problem description

Contrary to what is stated in the documentation of DataFrame.join(), when using the default sort=False, the return DataFrame preserves the index order of the other (right) DataFrame, instead of the index order of the calling (left) DataFrame.

Besides, the sort=True argument does not work.

#### Expected Output
The expected output is that the return DataFrame should preserve the index order of the calling (left) DataFrame.

#### Output of ``pd.show_versions()``

<details>
INSTALLED VERSIONS
------------------
commit: None
python: 3.5.2.final.0
python-bits: 64
OS: Linux
OS-release: 3.13.0-108-generic
machine: x86_64
processor: x86_64
byteorder: little
LC_ALL: None
LANG: ca_ES.UTF-8
LOCALE: ca_ES.UTF-8

pandas: 0.19.2
nose: 1.3.7
pip: 8.1.2
setuptools: 27.2.0.post20161106
Cython: 0.24.1
numpy: 1.11.1
scipy: 0.18.1
statsmodels: 0.6.1
xarray: None
IPython: 5.1.0
sphinx: 1.4.6
patsy: 0.4.1
dateutil: 2.5.3
pytz: 2016.6.1
blosc: None
bottleneck: 1.1.0
tables: 3.2.3.1
numexpr: 2.6.1
matplotlib: 1.5.3
openpyxl: 2.3.2
xlrd: 1.0.0
xlwt: 1.1.2
xlsxwriter: 0.9.3
lxml: 3.6.4
bs4: 4.5.1
html5lib: None
httplib2: None
apiclient: None
sqlalchemy: 1.0.13
pymysql: None
psycopg2: None
jinja2: 2.8
boto: 2.42.0
pandas_datareader: 0.2.1
</details>
