[Merge] [perl #109408] Documentation that refers to Perl 5 as new

[Merge] [perl #109408] Documentation that refers to Perl 5 as new

Quoting Brian Fraser:

So.
I more or less went ahead and did this, to some extent. To some other
extent the changes are stylistic, like consistently using v5.x.y instead of
5.x or 5.x.y or whatnot in perlvar (and only in perlvar, so as to avoid
bikeshedding). I also bumped most odd versions, post 5.6, to the next
stable release (so, for example, 5.7.1 became 5.8.0, and 5.9.0 became
5.10.0, but 5.005 is still 5.005).

There's only one big deletion, which was most of perltrap.pod -- It dealt
with traps for Perl 4 programmers migrating to Perl 5. It would be really
swell if someone could update perltrap for their other favorite language of
choice, since right now the document is severely lacking, only dealing with
awk, shell, C/C++, and Perl itself.

There's some stuff that I didn't really know about, so I left it alone,
including all of perlhack(tips)? and perl(re|deb)?guts.
One thing that came up in IRC while I was doing this is that having a table
in perlvar detailing in which version each variable became available would
be really swell. And I know that brian d foy compiled one for string/regex
escapes, which strikes me like a good candidate to get in as well.