separate fallback _numeric code from __init__
Initial commit
transfer files from nutils repo
lift writeable=False restriction for hash
add unit tests
add more unit tests
rename SaneArray to NumericArray
remove numeric module
Add 'nutils/numeric/' from commit 'c56adabaea8eb03fc35fc5482fd0f30dcc94e0b1'

git-subtree-dir: nutils/numeric
git-subtree-mainline: 89e9fb6ba212c25757130662d1c28b210f5b1ff8
git-subtree-split: c56adabaea8eb03fc35fc5482fd0f30dcc94e0b1