Fixed ofstream default constructor

the default mode parameter for the output stream was set to input which
resulted in the store_to_plain_array() to not work properly.
Remove an unused variable

There is an unused variable in suffix_array_algorithm.hpp.
Remove the variable and preserve the backward_search call.
Changed output method.
Added sdsl-qualifier.
Fixed compiler warnings.
Fixed compile warning.
Fixed typo
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
Fixed formatting
Fixed formatting
Fixed formatting
Fixed formatting
Asserts included