Update zap jar (zaproxy#1165)

Update zap jar 

Note that this is a pre release version for testing - I'll update the PR
with the final jar once all changes have been merged.

Includes changes to address deprecation.
Updated TestParameterTamperUnitTest to align with
zaproxy#899 (empty string for
"Attack" vs. null)

Merge pull request zaproxy#812 from thc202/selenium-browser-ids

selenium: document the IDs of the browsers

Updated to point to the zap-extensions 2.5 release

2.4 Release created in zaproxy