Added tutorial examples
Handled special case in lex_count
Handle special case in wt_pc.
Fixed bug in lex_count when m_sigma=1
Removed template class from include directory.

Such a class should rather be in the tutorial
directory of the project.
Merge branch 'tutorial' of github.com:simongog/sdsl-lite into tutorial
Addressed issue #88
Updated documentation.
Adjusted example.
Addressed issue #90 and added more examples.
Turned on optimization.
Adjusted to new inverse_select notation.
Fixed compile bug.
Adjusted to new lex_count signature.
Merge pull request #91 from simongog/tutorial

Tutorial