Fix PATCH button title in the template

For fixes in #1029, #1030 - Thanks!

Spelling correction on read_only_fields err msg

Spelling correction on read_only_fields err msg

just spotted extras

For multiple documentation fixes in #1026.  Thank you! :)

Fixed typos in a bunch of docs

Fix typos in routers.md

Add missing comma to generic view example.

Add drf-any-permission docs entry #1014

Renamed wrong filename in the browsable API documentation. 

Changed rest_framework/base_login.html to rest_framework/login_base.html (which is the correct name the user should extends in their templates).

Clarification to authtoken docs

Documentation detailing requirement to migrate prior to running `createsuperuser` if using an authtoken `post_save` signal.
Closes #987.  Thanks to @yprez.

Fix Tutorial5 serializers.py typo

[Issue #N/A]

A slight typo at Tutorial5 causing an Exception "name 'models' is
not defined". A subtle one that can confuse Python/Django noobs
like me.

Fixed arguments in assertion

Fix *Throttle class names in the docs

* AnonThrottle -> AnonRateThrottle
* UserThrottle -> UserRateThrottle
* ScopedThrottle -> ScopedRateThrottle
* (cosmetic) removed one errant whitespace character

Fixes #1006.

Updated EmailField error message.

added script block to list of blocks

Phew, was afraid I wouldn't be able to overwrite this section..