Remove submodule 'libopencash'
Squashed 'libopencash/' content from commit ddf623e

git-subtree-dir: libopencash
git-subtree-split: ddf623ef4f8d801e8b48d46f302de8becf098ec4
Merge commit 'c4e74cee35fb68df3338a736090da7947631e627' as 'libopencash'