Here you will find the Help documents for various releases.
Latest Development (probably not yet released).
1.6.20
1.6.19
1.6.17
1.6.16
1.6.14
1.6.12
1.6.11
1.6.10
1.6.7
1.6.6
1.6.5
1.6.4
1.6.3
1.6.2
1.6.1
1.6.0