move Help site away from threatdragon.org to threatdragon.github.io

Merge pull request OWASP#349 from OWASP/avoid-copyfiles

Avoid copyfiles: fixes OWASP#330 and fixes OWASP#328

update developer notes for release process

second release candidate for version 1.6.0

first release candidate for version 1.6.0

prepare for version 1.5.8 release

prepare for version 1.5.7 release

prepare for version 1.5.7 release

Version 1.5.5 release

fix context threat generation