Update the changelog

Merge pull request FriendsOfSymfony#1949 from XWB/verb

Use verb rather than noun

Update changelog for 1.3.6

Updated the changelog for 2.0.0-alpha1

This release is not considered as being representative of the final 2.0
API, but it allows locking dependencies given the time spent since the
beginning of the 2.0 development

Merge branch 'preserve_entropy' into 1.3.x

Updated the changelog for 1.3.4

Updated the changelog for 1.3.3

Updated the changelog for 1.2.5

Changed the flash message handling to use the non-deprecated api

This fixes the compatibility with symfony 2.3

Updated the changelog