Added travis configuration file.
Merge branch 'master' of github.com:simongog/sdsl-lite
Build all execs in project with travis.
Parallelize build.
Moved tree topology into separate class `byte_tree`.
Removed node_count variable.
Simplified pc_node struct.
Moved t_dfs_shape parameter into tree strategy class.
Removed unnecessary c_str() calls and replaced on

std::remove call by sdsl::remove.
Fixed template parameters.
Replaced magic numbers by constant.
Now POD-vectors can also be serialized and loaded.
First working version of integer versions of HuTucker

and Huffman-shaped wavelet trees.
Fixed serialized method.
static const integer consts -> enum
Removed use of `undef`-node in wt_pc.
Removed use of `undef`-node in wt_pc.
Fixed structure tree node merge.