Preserve entropy in TokenGenerator

base_convert loses precision on large inputs. Use URL-safe base64_encode instead.
lt  grammar mistakes
Merge pull request #1076 from aur1mas/master

Lithuanian translation grammar mistakes
Update propel.xml
Merge pull request #1089 from ClementGautier/patch-1

Added FOS message to the propel validation
added "Annotations" namespace for mongodb
Merge pull request #1099 from bartrail/master

docs: added "Annotation" namespace for MongoDB user and group classes
Enforce POST for /login_check
Used 2.1 syntax
Updated the constraints to allow Symfony 2.3

Closes #1107
Closes #1085
Merge pull request #1103 from kbond/patch-1

Enforce POST for /login_check
Merge pull request #953 from jmclean/patch-1

Preserve entropy in TokenGenerator