upgrade deps, disable use of bundle exec
remove unnecessary escaping of callouts
resolves #169 adds safe modes to user manual

- adds security section to user manual
- updates appendix a with safe mode attributes
- relates to issue #125
Merge pull request #170 from graphitefriction/security

resolves #169 adds safe modes to user manual
resolves #172 cleans up the block summary in the user manual
add information about inline anchors
Merge pull request #173 from graphitefriction/block-summary

resolves #172 cleans up the block summary in the user manual