[security] adding a tip about supported algorithm for 'hash' function
use a phpfunction link + vocabulary change (method -> function)
Merge pull request #3325 from FlorianLB/supported_algorithms

[WIP] [security] adding a tip about supported algorithm for 'hash' function
Merge branch '2.2' into 2.3
Clarifying some details on serialize/unserialize and making it consistent with changes we recently made
Merge remote-tracking branch 'origin/2.3' into 2.3
[#3326] Tweaks to voter wording