Prepare new 1.5-11 release

[vincentvanhees]

• Update change log in NEWS.Rd summarizing the new features added by Jairo + and the key items listed in Expandtests #41.
• Updare version number and add Jairo as contributor in DESCRIPTION file and GGIR-package.Rd

[vincentvanhees]

looks good, I have one minor improvement to the g.wavread function I would to prepare before we can upload this to CRAN... I will try to do this evening