Encode the "vX" part in distfiles, translated as "plX" in PKGNAME.
Makes it possible to update to v2.48.15v4, which is needed with newer
OCaml version.
ok sthen@ bket@ (maintainer)
This version is not compatible with older versions, so retain 2.48.15 by
splitting into 2.4x and 2.5x subdirectories and using "@option
is-branch".
Initial diff has been looked at by kn@ (looks OK port- and build-wise on
amd64) and giovanni@ (OK). Issues found by sthen@ (thanks!) and fixed by
me.
Take MAINTAINER (as discussed with giovanni@).
OK sthen@