fix some gcc-7.3 warnings

[mjtrangoni]

I fixed some trivial gcc warnings. Please feel free to merge or cherry-pick some.

Thanks!

[hedenface]

Thanks! Can you resolve the conflicts for maint so that I can review and merge?

[mjtrangoni]

@hedenface thanks! It should be working now. I forgot you work with the maint branch.

[mjtrangoni]

@hedenface this is a little chaos here, I will be fixing and rebasing this soon.
What's about setting up TravisCI here too?

[hedenface]

I had asked @box293 to look into creating one for plugins. If you'd like to work on that, feel free!

All of the OSS projects will have some form of testing in the next few months - along with a more consistent layout and the beginnings of consistency throughout the codebase(s). I'm actually working on the style guide for Core as we speak and that should be available soon.

[chicks-net]

Where will the style guide be once it is available? Or where should we keep an eye out for the style guide announcement?

[hedenface]

It will be available in each of the repos as CODING_STYLE.md once complete.