Merge branch 'feature/gradient-aware-truncation' into 'master'

Allow to make truncation gradient aware

See merge request !27
4 jobs for master in 7 minutes (queued for 7 seconds)
Status Name Job ID Coverage
  Test
passed dune:git clang C++17 #176767

00:04:24

passed dune:git clang C++17 with examples #176769

00:06:59

passed dune:git gcc-8 C++17 #176768

00:06:25

passed dune:git gcc-8 C++17 with examples #176770

00:02:53