Document that length-aware string functions have been added in 2.7
Document that length-aware string functions have been added in 2.7

Mephistophiles/jansson,bstarynk/jansson,markalanj/jansson,akheron/jansson,AmesianX/jansson,AmesianX/jansson,akheron/jansson,bstarynk/jansson,markalanj/jansson,markalanj/jansson,akheron/jansson,Mephistophiles/jansson,bstarynk/jansson