This class had slightly confusing semantics and the added weirdness
doesn't seem worth it just so we can say "." instead of "->" when
iterating over a vector of NNRPs.
This patch replaces NonnullRefPtrVector<T> with Vector<NNRP<T>>.
It is now possible to quickly switch to specific tabs directly without
having to 'search linearly'.
Pressing Ctrl plus a number from 1 to 8 switches to the tab of that
index. Pressing Ctrl-9 swithes to the last tab.
This feature already exists in Firefox and Chrome.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
