add Coverity Scan to check for possible issues

[GitMensch]

This is just an idea but can be a nice addon. It can be done "manually" or (why not) be integrated to run by Travis (normally when merging to a special branch).

Coverity Scan is a static code analyzer that checks the code for possible issues. Another option would be to run each port through a static analyzer manually and create issues for these.

For some details see https://scan.coverity.com/travis_ci
@Bill-Gray Please consider or close this issue.

[GitMensch]

Ping @Bill-Gray As you are the repo owner you are the only one that can sign in there (and may "invite" me to fix some of the minor issues ;-)
What do you think about this?

In the case you aren't interested in this, then please drop a note and close this issue.