Rectified some "personal comments"
Updated make script & named logo image as done in asciidoc
Added clean script
Apparently current version of asciidoctor (ruby/git-hub) does not
render text blocks as do asciidoc. If starting block delimiter char
number is different from final block delimiter char number, asciidoctor
misses the end of the block. I made it the same to avoid this strange
behaviour (and filed a bug report to asciidoctor).
Updated Italian translation
Update Makefile also with a new help message
Deleted the "made with dblatex" sign in pdf first page.
Small typos
Upgraded makefile (new global variables)