Problem: To goto or delete a bookmark, one needs to prefix a count
for the bookmark number (e.g., "2gb" to open bookmark#2).
As the bookmark list gets or deletes entries, the numbers
keep changing, requiring listing the bookmarks with qb to
discover the desired bookmark number. Typing gb or mB
without a count targets g:netrw_bookmarklist[-1].
Solution: If no count is given to gb or mB, list all bookmarks and
prompt for a number using inputlist(), similar to tag jump
with g].
closes: vim/vim#2021135b767a090
Co-authored-by: J. Paulo Seibt <jpseibt@gmail.com>
3bc21c0903
