Main benefit would be that we can get rid of the Python dependency that ExcelReaders.jl brings along and still support both old a new Excel file formats. The Python dependency has been problematic pretty regularly in terms of deployment.

Stuff still todo:

• get LibXLS.jl in shape. I got the cross building sorted out, and I have some local code that can read meta data from old school Excel files, but there is still a lot to finish before this is ready.
• Do some performance comparisons of ExcelReader.jl and XLSX.jl, just to be sure (I don't really expect any real issues there)
• Code things up here :)

CC @felipenoris