Move range.adapter to algorithms + take() bugfixes

A lot of algorithms like lazy sort() can be also classified as adapters
since it wraps the original range and allows to access the elements of
the range in a particular order. The only reason why take() was in
range.adapter is that take() is trivial - it doesn't change the order of
elements but can turn an infinite range into finite one. This
distinction between trivial and non-trivial algorithms isn't absolutely
clear. So let us put all algorithms and any adapters that change the
range iteration in some way into "algorithm" package to avoid any
confusion later.

- range.adapter is renamed into algorithm.iteration
- range.adapter is deprecated
- Added missing imports for take() and takeExactly()
- takeExactly() doesn't wrap ranges that have slicing anymore
- Voldemort structs for take() takeExactly() are now static

source/tanya/algorithm/package.d

@@ -15,4 +15,5 @@
 module tanya.algorithm;
 
 public import tanya.algorithm.comparison;
+public import tanya.algorithm.iteration;
 public import tanya.algorithm.mutation;