Rename Marconi to Zaqar

This patch renames every package, file, match of Marconi in the codebase
to Zaqar *except* for the .gitreview file, which will have to be updated
*after* I8e587af588d9be0b5ebbab4b0f729b106a2ae537 lands.

Implements blueprint: project-rename

Change-Id: I0c82be81f74d022ab609eea8f40ac2c0635374b1
Merge "Rename Marconi to Zaqar"