enable web fonts in stylesheet
refactor conversion and rendering code

- use clearer ipc message name
- allow XHR to work for local files
- better error message when XHR fails
- improve method names
- remove use of double quotes where unnecessary
bump max version
add dollar sign before command in README
set safe to server by default to enable includes
set implicit attributes; no need to disable toc
Merge pull request #19 from mojavelinux/code-review

Code review