v2.19.5: Fix man page bold rendering as N<NA<AM<ME<E

Before this release, man pages formatted by groff 1.22.4, which ships
with for example Ubuntu 22.04, could show bold text, underlines and
bullets as letters separated by red '<' markers. That version of groff
sometimes repeats each overstruck character to make it look extra bold,
and moor did not recognize those repeats.

With this release, moor renders those repeats as regular bold, underline
and bullets, and searching and copying text from such pages works as
expected. Thanks @yermulnik for reporting
#472!