This PR seems rather big.
I should have made smaller bits.

1. It is the result of discoveries made when trying to pass the conformance tests.
   These are passing entirely now.

The issues where raised in :

• 404 on DELETE fictive Resource solid-contrib/specification-tests#112
  acl-check for DELETE was wrong and needed access to resource ACL but also to parent resource ACL
• http to https : timeout with OPTIONs on NSS solid-contrib/specification-tests#113
  http to https : http not acccessible in the tested instance
• If-none-match on NSS returns 201 for PUT on existing resource solid-contrib/specification-tests#115 :
  precondition if-none-match=* should return 412 for PUT on existing resource
• with NSS returns : $ | data types don't match (LIST:STRING) solid-contrib/specification-tests#116
  NSS was mistakenly returning Content-Type: application/octet-stream; charset=utf-8 for HEAD on Container
  Erroneous contentType on container

Tests have been added

2. it includes also

• APPEND for PUT on resource creation
• control that same name do not occur on the creation of intermediate container

and tests