Update events.rst

Part translation in french
Merge pull request #1929 from blackpuppy/zh

[zh_CN] done /zh/models/callback-methods.rst
Update rest.rst
Merge pull request #1930 from ywdx/patch-1

Update rest.rst
[fr] typos
[fr] corrections
Make note of xdebug support for fatal stack traces

https://github.com/cakephp/cakephp/pull/5053
Merge pull request #1943 from ionas/patch-2

Make note of xdebug support for fatal stack traces
[fr] follow #1943
[fr] corrections orthographiques
getPeady=>getReady

getPeady=>getReady
Merge pull request #1947 from zx4357685/patch-2

getPeady=>getReady
Removed serbian translation for 2.0, too

Refs https://github.com/cakephp/docs/pull/1948

Turns out the serbian translation isn't kept up to date for 2.0 either.
No wonder when the initial maintainer  "Aleksa-Savic" disappeared.

The commits in this tree are not many:
https://github.com/cakephp/docs/commits/master/sr
Removed romanian translation for 2.0, too

Refs https://github.com/cakephp/docs/pull/1948

The Romanian translation was started but not kept up to date for quite some time now:

The commits in this tree are not many:
https://github.com/cakephp/docs/commits/master/ro
Merge pull request #1949 from cakephp/2.0-serbian-removal

Removed serbian translation for 2.0, too
Merge pull request #1950 from cakephp/2.0-romanian-removal

Removed romanian translation for 2.0, too
Added a How to Install Plugins guide
Merge pull request #1951 from cakephp/2.x-how-to-install-plugins

Added a How to Install Plugins guide
Merge pull request #1539 from ExtraBlind/patch-1

Update events.rst
update after #1539