Merge branch 'ofe' into 'master'

split completion from COFEs and only require it for the solver

This is the OFE part of !22 

Cc @robbertkrebbers @jjourdan

See merge request !26
1 job for master in 10 minutes and 20 seconds
Status Job ID Name Coverage
  Test
passed #1377
coq
buildjob

00:10:20