idea taken from homedecor_modpack and its homedecor_i18n
all translated mods have a new dependency : plantlife_i18n
translations are stored in po/pot file : one file for all mods

added french translation (almost complete)
transfered de/es/tr/pt translations to corresponding .po file
(only for some mods, unfortunately translations are incomplete)

Conflicts:
	nature_classic/init.lua

This happens when the ABM runs after the block has been unloaded
for much longer than the ABM interval: in that case, the initial
ABM running chance for a node in the block may become up to 100%.

Because minetest.after() is not bound to a position, and because it is not
saved, it may trigger after the node to which it applies was unloaded, or
not at all (if the session ends). If that happens, The 'young' flag
will not be cleared, and will have become persistent (i.e. without a timer
which will eventually clear it).

This patch removes the 'young' flag, and replaces it with a timestamp, removing
the need for a timer. Any lingering 'young' flags that have become persistent
are automatically removed over time (i.e.: they are simply ignored...)

It didn't, so that all apple leaves would permanently become blossom
over time.

don't use minetest.env:* method (deprecated), use minetest.* instead

If moretrees is not present, nature_classic spawns blossoms and
eventually apples on default trees, as it always has.

If moretrees IS present, the code will only spawn apple blossoms on
moretrees' own apple tree leaves, and will only grow new apples on those
trees, not on default trees.  In this case, the nature:blossom node is
considered deprecated and is aliased to default:leaves to avoid causing
undefined nodes in old maps.

blossoms/apple spawning portion only
does not include the iron trees or tree-growing code as those are obsolete