Convert to native datatypes for Series.tolist()
- [x] closes #10904
- [x] tests added / passed
- [x] passes `git diff upstream/master | flake8 --diff`
- [x] whatsnew entry

## [Current coverage](https://codecov.io/gh/pydata/pandas/pull/13050?src=pr) is **84.15%**

> Merging [#13050](https://codecov.io/gh/pydata/pandas/pull/13050?src=pr) into [master](https://codecov.io/gh/pydata/pandas/branch/master?src=pr) will increase coverage by **+<.01%**

``` diff
@@             master     #13050   diff @@
==========================================
  Files           137        137          
  Lines         50261      50214    -47   
  Methods           0          0          
  Messages          0          0          
  Branches          0          0          
==========================================
- Hits          42288      42253    -35   
+ Misses         7973       7961    -12   
  Partials          0          0          
```
1. 2 files (not in diff) in `pandas/tseries` were modified. [more](https://codecov.io/gh/pydata/pandas/commit/18ccde40e16df2a019f770c599cfaa317a4b9433/changes?src=pr#70616E6461732F74736572696573) 
   - Misses `-4` 
   - Hits `-22`
2. 2 files (not in diff) in `pandas/io` were modified. [more](https://codecov.io/gh/pydata/pandas/commit/18ccde40e16df2a019f770c599cfaa317a4b9433/changes?src=pr#70616E6461732F696F) 
   - Misses `-3` 
   - Hits `-3`
3. 2 files (not in diff) in `pandas/core` were modified. [more](https://codecov.io/gh/pydata/pandas/commit/18ccde40e16df2a019f770c599cfaa317a4b9433/changes?src=pr#70616E6461732F636F7265) 
   - Misses `-5` 
   - Hits `-8`
4. 1 files (not in diff) in `pandas` were modified. [more](https://codecov.io/gh/pydata/pandas/commit/18ccde40e16df2a019f770c599cfaa317a4b9433/changes?src=pr#70616E646173) 
   - Hits `-2`

> Powered by [Codecov](https://codecov.io?src=pr). Last updated by [1296ab3...18ccde4](https://codecov.io/gh/pydata/pandas/compare/1296ab39d32acaf2c77ed0c185fafe4ebcfedcb3...18ccde40e16df2a019f770c599cfaa317a4b9433)
 I will correct this under `2.7`

```
======================================================================

FAIL: test_tolist_np_uint (pandas.tests.series.test_io.TestSeriesIO)

----------------------------------------------------------------------

Traceback (most recent call last):

  File "/home/travis/build/pydata/pandas/pandas/tests/series/test_io.py", line 93, in test_tolist_np_uint

    for t in ['uint8', 'uint16', 'uint32', 'uint64']]

AssertionError: <type 'long'> != <type 'int'>

----------------------------------------------------------------------
```
 Please review
 needs a whats new with an example
 added whatsnew
 Please review
 thanks @gliptak 
