Added method bounds and fixed a bug in interval_symbols
Fixed a bug in interval_symbols
Added tests for inverse_select, interval_symbols and bounds
Added bidirectional-search
Added a HuTucker-Shaped Wavelet Tree
Added wt_hutu to the tests
Enabled bidirectional search for HuTucker-Shaped Wavelet Tree
Fixed formatting
Asserts included
Fixed compile error
Fixed comments
Minor changes according to discussion with Simon
Minor changes
Removed tabs
Renamed methods
Inserted forward declarations.

Otherwise it won't compile.
Removed unnecessary constructor, renamed construction method.
Structured classes for merge.
Factored out the construction of the shape.
Consistent naming of template parameters.