BUG: coercion of mixed dt-aware data in Series constructor
I ran into an issue where the behavior of `.apply()` changed from 0.16 to 0.17, causing different results on tz aware data. Extracting the hour of day from datetimes is different for `Series(x).apply(func)` vs `func(x)`. Below is a minimal example of the issue in 0.17, it seems the behavior is the same in 0.18 but different (though still not equal) on master, also shown below.
#### On 0.17.1 and 0.18.0:

``` python
>>> import pandas as pd
>>> def hour_of_day(dt):
...     return dt.hour
...
>>> dt = pd.to_datetime(1462068217, unit='s')
>>> dt_localized = dt.tz_localize('UTC').tz_convert('US/Pacific')
>>> dt_list = [dt, dt_localized]
>>> apply_series = pd.Series(dt_list).apply(hour_of_day)
>>> map_series = pd.Series(map(hour_of_day, dt_list))
>>> print dt_list
[Timestamp('2016-05-01 02:03:37'), Timestamp('2016-04-30 19:03:37-0700', tz='US/Pacific')]
>>> print apply_series
0    2
1    2
dtype: int64
>>> print map_series
0     2
1    19
dtype: int64
>>> print apply_series - map_series
0     0
1   -17
dtype: int64
>>> pd.show_versions()

INSTALLED VERSIONS
------------------
commit: None
python: 2.7.11.final.0
python-bits: 64
OS: Darwin
OS-release: 15.2.0
machine: x86_64
processor: i386
byteorder: little
LC_ALL: None
LANG: en_US.UTF-8

pandas: 0.17.1
nose: 1.3.7
pip: 8.1.1
setuptools: 20.7.0
Cython: 0.24
numpy: 1.11.0
scipy: 0.17.0
statsmodels: None
IPython: 4.2.0
sphinx: 1.4.1
patsy: 0.4.1
dateutil: 2.5.2
pytz: 2016.3
blosc: None
bottleneck: 1.0.0
tables: 3.2.2
numexpr: 2.5.2
matplotlib: 1.5.1
openpyxl: 2.3.2
xlrd: 0.9.4
xlwt: 1.0.0
xlsxwriter: 0.8.5
lxml: 3.6.0
bs4: 4.3.2
html5lib: 0.999
httplib2: None
apiclient: None
sqlalchemy: 1.0.12
pymysql: 0.6.7.None
psycopg2: None
Jinja2: None
```
#### On 0.16.2 (what I expected):

``` python
# Same setup as above
>>> print apply_series
0     2
1    19
dtype: int64
>>> print map_series
0     2
1    19
dtype: int64
>>> print apply_series - map_series
0    0
1    0
dtype: int64
>>> pd.show_versions()

INSTALLED VERSIONS
------------------
commit: None
python: 2.7.11.final.0
python-bits: 64
OS: Darwin
OS-release: 15.2.0
machine: x86_64
processor: i386
byteorder: little
LC_ALL: None
LANG: en_US.UTF-8

pandas: 0.16.2
nose: None
Cython: None
numpy: 1.10.4
scipy: None
statsmodels: None
IPython: 4.2.0
sphinx: None
patsy: None
dateutil: 2.5.2
pytz: 2016.3
bottleneck: None
tables: None
numexpr: None
matplotlib: None
openpyxl: None
xlrd: None
xlwt: None
xlsxwriter: None
lxml: None
bs4: None
html5lib: None
httplib2: None
apiclient: None
sqlalchemy: None
pymysql: None
psycopg2: None
```
#### On master:

``` python
# Same setup as above
>>> print apply_series
0    19
1    19
dtype: int32
>>> print map_series
0     2
1    19
dtype: int64
>>> print apply_series - map_series
0    17
1     0
dtype: int64
>>> pd.show_versions()

INSTALLED VERSIONS
------------------
commit: 05e734ab171be0fda838c6b12839c38fa588da2c
python: 2.7.11.final.0
python-bits: 64
OS: Darwin
OS-release: 15.2.0
machine: x86_64
processor: i386
byteorder: little
LC_ALL: None
LANG: en_US.UTF-8

pandas: 0.18.0+203.g05e734a
nose: None
pip: 8.1.1
setuptools: 20.7.0
Cython: None
numpy: 1.10.4
scipy: None
statsmodels: None
xarray: None
IPython: 4.2.0
sphinx: None
patsy: None
dateutil: 2.5.2
pytz: 2016.3
blosc: None
bottleneck: None
tables: None
numexpr: None
matplotlib: None
openpyxl: None
xlrd: None
xlwt: None
xlsxwriter: None
lxml: None
bs4: None
html5lib: None
httplib2: None
apiclient: None
sqlalchemy: None
pymysql: None
psycopg2: None
jinja2: None
boto: None
pandas_datareader: None
```
#### Expected Output

I would expect the output to be [2, 19], as in 0.16, and matching map(f, data). 
