Make options for random rivers. Now they will not follow biome borders.
Simplification array cache and layers code
Testing rivers with dynamically height. Working only with RandomRivers = true.
Clear noise generator class.
Merge from master
Merge branch 'master' into BetterRivers
Rename badly named things in chunk generator class. Also remove some redundant variables.
Add river height and volatility options to biome config. Still dirty and work only if RandomRivers = true. Underground rivers and dynamic water level on the way.
River water level test.
Fixed edges of rivers

The water doesn't flow yet. Somehow, the biome height/volatility needs
to adjust the river a little bit.
Merge remote-tracking branch 'origin/master' into BetterRivers

Conflicts:
	common/src/com/khorn/terraincontrol/generator/ChunkProviderTC.java
Merge remote-tracking branch 'origin/master' into BetterRivers
Add RiverCustomHeightControl. Add comments.

- Rename RandomRivers to ImprovedRivers. Doesn't autoconvert.
- CustomHeightControl (and RiverCustomHeightControl too) won't clear
itself anymore when the number of elements is incorrect. Instead, it
will simply keep what fits. Should save a few headaches.
Move biomelayers to biome generators.
Split ImprovedRivers to two settings: RandomRivers and ImprovedRivers.
Add variable OutputType to biome methods in LocalWorld. Now this methods may return full biomes, without rivers and only rivers.
Add DEFAULT_FOR_WORLD to OutputType

This replaces the null-values.

- Some methods now throw an exception on failure instead of silently
returning null.
- Added comment for RandomRivers.
- Updated comment for ImprovedRivers.
- Made constants in OutputType uppercase to indicate that they are
constants.
- Replaced hardcoded check for old generator.
Fix mistakes in previous commit
Merge branch 'BetterRivers'