Chdir to input directory so Asciidoc includes work

[jkleint]

Currently the Asciidoc filter will only include:: files from the current working directory, which is smart. However, github doesn't change the CWD to the directory containing the file being rendered, so includes don't work.

[mojavelinux]

Actually, the issue is that the include::[] macro is intentially disabled on GitHub. We need to discuss if there is a safe way to allow it. One propose is to have custom include resolves in Asciidoctor, which would allow Gollum to include content from the known set of wiki pages.

Please chime in on this issue: https://github.com/erebor/asciidoctor/issues/100

(We need to get the API right).

[jkleint]

Wow. I'm sure there are many good reasons I don't fathom, but from the perspective of a random passerby, that looks like a serious case of NIH. My 2¢, respectfully: chroot sandbox asciidoc and get home early.

[bkeepers]

Same as #172 (comment)

[mojavelinux]

Asciidoctor has a programmatic extension point which gives you 100% control over the handling of an include directive. If you could provide me some information about what API is available to access the current GitHub repository, I'd be glad to work up a prototype that reads includes from the git tree for you to test. You can post information here or drop me a PM / email.