Remove files that are still there after an upgrade from 2.5 to 3.x

See: https://github.com/joomla/joomla-cms/issues/5326 by @ITPrism 

#### Quote from #5326 
```
Hi.
I upgraded my site from J!2.5 to J! 3.3.6 and I did some comparisons with a new copy of Joomla! 3.3.6 to check the differences.

It seems, the process of upgrading misses some things and some files and folders still exist.
I am posting a list of files and folders that still exists.

**Folders**
_/administrator/components/com_config/views_
_/administrator/components/com_config/models/fields_
_/administrator/components/com_config/models/forms_

**The files in that folder**
_/administrator/help/en-GB_

**Files**
_/libraries/joomla/environment/request.php_
_/media/editors/tinymce/templates/template_list.js_

**The plugin Geshi ( plg_content_geshi ) still exists.**
_/plugins/content/geshi_

**SQL**
There is a difference in the definition of the column "**_content_history_options_**" in table "**_#__content_types_**".

After upgrade from J! 2.5 to J!3.3.6 it is **DEFAULT ""**.
After a new installation of J!3.3.6 it is **DEFAULT NULL**.

Regards,
T
```

This handels only the files and folders. I don't know how the sql updates work that need to be added here. Also i don't know what is the correct `NULL` or `""` Thanks.