WIP/ENH: reading older Stata versions, #11526
A simple file seems to read OK if we just treat it like other "old format" (version 104-115) files.  However I do not currently have any documentation for this format.  The only relevant resource I can find is the file `foreign/src/stataread.c` in the R `foreign` package sources:

https://cran.r-project.org/src/contrib/foreign_0.8-66.tar.gz

It suggests some special handling for version 111 but I haven't had time to figure out exactly what it is doing.
- [x] closes #11526 
- [x] tests added / passed
- [x] passes `git diff upstream/master | flake8 --diff`
- [x] whatsnew entry

## [Current coverage](https://codecov.io/gh/pydata/pandas/pull/14159?src=pr) is 85.24% (diff: 100%)

> Merging [#14159](https://codecov.io/gh/pydata/pandas/pull/14159?src=pr) into [master](https://codecov.io/gh/pydata/pandas/branch/master?src=pr) will not change coverage

``` diff
@@             master     #14159   diff @@
==========================================
  Files           140        140          
  Lines         50563      50563          
  Methods           0          0          
  Messages          0          0          
  Branches          0          0          
==========================================
  Hits          43101      43101          
  Misses         7462       7462          
  Partials          0          0          
```

> Powered by [Codecov](https://codecov.io?src=pr). Last update [6c73e76...34e09ef](https://codecov.io/gh/pydata/pandas/compare/6c73e765a5f1191c954c7789791818d2685c3c2c...34e09ef9fafd6f25e6e50fcd611fcf28b776ca2b?src=pr)
 can you add a whatnew in Bug Fixes. ping on green.
 can you rebase and push again
 @jreback I don't understand the issue with appveyor here
 need to rebase on master
 @jreback, looks OK now
 thanks!
