This changes the buildlink3.mk files to use an include guard for the
recursive include. The use of BUILDLINK_DEPTH, BUILDLINK_DEPENDS,
BUILDLINK_PACKAGES and BUILDLINK_ORDER is handled by a single new
variable BUILDLINK_TREE. Each buildlink3.mk file adds a pair of
enter/exit marker, which can be used to reconstruct the tree and
to determine first level includes. Avoiding := for large variables
(BUILDLINK_ORDER) speeds up parse time as += has linear complexity.
The include guard reduces system time by avoiding reading files over and
over again. For complex packages this reduces both %user and %sys time to
half of the former time.
Please see the release notes online[1] for the list of fixed bugs.
Also, the license was wrong. There are several differences in all clauses
between the 1.3 and 6 licenses, so add the proper license files.
[1] http://java.sun.com/javase/6/webnotes/ReleaseNotes.html
(true for 1.5, but officially branded as such for 6), so this is called
"sun-j{dk,re}6" rather than "sun-j{dk,re}16".
amd64 support is not currently included, but initial provision exists in
the sun-jre6 package as it was cloned initially from sun-jre15.
