Use two SparseBitVectors in RLEWavelet

fiwiki.ilcp is now ~75MB
Moved bit-vector tests to bit-vector_test

Tests are now with type-parameter.
Implement faster rank/select for FastBitVector

Uses Vigna's ideas to store rank for each 2048-bit block and partial
rank for each 384-bit part of that. Reduces cache misses: only two
cache misses are now even possible for one rank query. This has
128/2048 = 6.25% overhead.

Select structure stores rank-block of each 8192'th 1/0. Then binary
search is used to find the correct rank-block and linear search to find
the sub-block. This has 64/8192 = 0.7% overhead.