ecltree updated

[Robin Fairbairns]

the ecltree macros, which have been dormant for *ages*, have now been
updated, by frank mittelbach with the authors permission, for better
performance with current latex.  (in parallel, i've done minor
modernisation of the documentation.)

i've installed the new version in macros/latex/contrib/eclbip (the
old macros/latex209/contrin/eclbip directory has moved to the the
obsolete/ tree).

the licence is now lppl.

Robin Fairbairns

For the CTAN team