Move index.md => index.html

in order to have more fine-grained control over markup.
Allow passing arbirtrary arguments to servelocal.sh
Re-introduce footer on index page
Add custom excerpt plugin and rework front page
Extract variables to simplify excerpt processing
Experiment with main page CSS
Rewrite stream.sh as 'post' and 'ptime' commands
Experiment further with styling
Add include for listing logs on project pages
Cease stripping slashes from category paths

Replacement is too greedy; strips not only slashes at the end, but also
in the middle.
Add #logs to german project page
Add projects/german//_posts/2014-07-09-hausübung.md
Rename post to plain ASCII
Remove test post
Use unique post slug for german homework