WorldGuard integration - UNTESTED
Make sure we check if there is a region manager.

Worlds may not have a manager, in which case the world is
going to be unprotected.
Update with WG stuff.
Tested WorldGuard code - works.

I created a protected region, and ran several thousand
erosion cycles over gravel under water inside, and outside
the worldguard region. Only the area outside the worldguard
was modified. Also tested everything works without WG
installed, and adjusted the README.
Also deposit into lava

This makes the plugin consider lava equivalent to water and
blocks will fall -into- lava pools and streams, just like
they can fall into water.
Attempt to make waterfalls behave more natural

With the old code, waterfalls would only ever grow and
the amount of water blocks would never decrease. This
leads to huge pillars of water that are unrealistic and
create enormously large water fans, which is ugly at
best.

This code removes the water column entirely above blocks
that are moved. By doing so, we cause a waterfall block
update which will likely put the water back again, but
most of the time do so one block lower. This causes the
water depth to be adjusted continuously lower, and leads
to a more realistic flow.

Ultimately, this code will also remove the waterfall
itself since it will remove the water origin block as
well if it is no longer protected. Since the landscape
generator usually put waterfalls *under* another stone
block, this will take a long time. All water will disappear
and you're left with a "dry" valley and alluvial fan below,
which bears resemblance to dry valleys in nature.
Merge branch 'master' into glacier

Conflicts:
	src/org/foo_projects/sofar/Sedimentology/Sedimentology.java
Don't stack snow up high on vegetation.
clay: also don't create clay above sealevel.

There's otherwise still clay blocks being made in waterfalls
in river biomes, which looks weird once the waterfall
retreats.
Don't need temperature anymore.
Fix snow melt. Snow is crushable too.
Snow accumulation rewrite.

No longer recursive, and tweaked all the parameters to be
a bit simpler and easier to check. The end result is a lot
better than before, since I broke quite a few aspects as
I was going through this code.

Pretty smooth snowy hilltops, growth is smooth as well.

Thawing is done right at the start which simplifies and
makes things a bit faster.
Mostly more glacier-style fixes.

- found a missing break causing stone never to decay
- a thick snow cover will break down everything down to gravel, but
  not to dirt. Grass will still become dirt. This makes mountains
  that are covered with snow become gravel producers
- under snow degradation goes faster, but displacement stays behind
  a bit as it did before.
- lots of minor adjustments