New font stack

Serif: EB Garamond
Sans-serif: N/A
Monospace: Source Code Pro
Fixed the \pack macro
Scaling of Source Code Pro fixed
Updated EB Garamond to 0.015d
Added feature selection to EB Garamond
Add math font. Add microtype config.

There's something going on with \setmathfont, which makes it break.
Feels like a bug but could be my bad.
Fix minor error in fonts.tex

Still won't work with unicode-math :(
Added (ugly) bold Garamond variant