Global/local options

[tnagler]

E.g., vinecop(data, vinecopulib_options(keep_data = FALSE))

[tvatter]

We had a quick chat on this issue, but I can't remember what we decided.

?

[tnagler]

Hm yeah, me neither. One thing we discussed was having global rvinecopulib options() to change the default of e.g. the cores argument. The other was to have objects similar to our controls in cpp. No idea what we decided and why :D