Fix Perl warnings

Origin: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=771004
Update to 0.5.3+debian-19+
Merge branch 'feature/debian-version'
Merge branch 'bug/w3mman2html-utf8'
English fixes

Origin: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=766550#25
Tweak for W3MMAN_W3M

Origin: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=771003#5
Add more info on configuration

Origin: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=766550#30
Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=268211
Note that -cols only affects when HTML is rendered

Origin: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=766550#30
Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=285251
Improve explanation about option -N

Origin: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=766550#30
Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=345084
Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=530468
Improve EXAMPLES

Origin: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=766550#30
Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=380560
Improve FILES

Origin: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=766550#30
Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=403634
Merge branch 'bug/lang-en'