A lot of work and progress has been made since my last update. Version 0.2.0 has been released.
A lot of the technical stuff has been streamlined and optimized. Have moved away from only using sed to also trying, and using, Perl and awk.
One of the most important update is the ability to write your site using Markdown.
To achieve this, I tried a lot of tools and the problem I always ran into was that the tools always wrote to stdout and left the buffer empty.
In the end, I decided to use Pandoc and during my tests, it works flawlessly.
For now, it only works on Pages and not on Blogs.
This functionality will come in a later update.
You can follow the progress on GitHub.