Revert "deps: Fix 32-bit build of lib{unibilium,termkey,tickit}"

This reverts commit f76df2475356add68212d737acd7da5bba3b64d6.
deps: Fix unibilium/libtickit URLs
Merge PR #1620 'Fix 32bit unibilium build'
clipboard: support separate '+' and '*' clipboards
clipboard: handle linewise/charwise selections correctly
clipboard: clean up unnamedclip logic
change option "unnamedclip" back to "clipboard=unnamed/unnamedplus"

This allows to configure which of '*' and '+' should be used for
the unnamed clipboard
clipboard: better error message when provider not available
FIXUP: warn only once when unnamed[plus] and no provider
clipboard: add functional test
clipboard: fix `let @+ = ...` and add test
eval_has_provider: search autoload scripts same order as call_func
WIP: test null handling
api: Handle NULs and newlines in buffer_*_line.
FIXUP: simpler null test