Address peer review comments for some code clean-up #8

Peer review of the LEDAPS source code have identified the following two items 
that should be addressed:
1) The 6S part of code and calls to them are not very well commented.
2) There are lots of commented out code in different applications, for example 
in "lndsr" and "lndcal" parts of code, maybe the unused code there are better 
kept in the release for some purposes?