Remove old safe_netrc implementation in favour of third-party dependency

See merge request !21

instead just depend upon the third-party safe-netrc package, which is now available in all of the necessary places

Restructure CI to improve build and in-situ testing

See merge request lscsoft/lvalert!25

this package doesn't depend upon safe-netrc (yet)

that should be included by the builder, so that we can support fedora (you never know)

Remove m2crypto dependency

See merge request lscsoft/lvalert!24

Add monkeypatch for sleekxmpp issue

See merge request lscsoft/lvalert!23

Correct GPL license version

See merge request !22

the packaging says GPLv2+, but the code says otherwise

this is reproduced from emfollow/sleek-lvalert@2fabc824

Add copyright statements relating to sleek-lvalert

See merge request lscsoft/lvalert!20

A bunch of code was forked from sleek-lvalert without any original copyright attribution.

tweaked the user's guide with up-to-date information

Don't try to process .netrc file if username and password are both provided to LVAlertClient

See merge request lscsoft/lvalert!18