Remove unnecessary comments

Signed-off-by: Niko Rosvall <niko@ideabyte.net>
Add missing function comments.

Even some function names are self-explanatory, it's still good to have
couple of lines to explain them.

Signed-off-by: Niko Rosvall <niko@ideabyte.net>
Add mark_old_as_done function skeleton

Signed-off-by: Niko Rosvall <niko@ideabyte.net>
Merge branch 'master' of https://github.com/tripples/memo into temp
Remove -Werror flag from the Makefile.

-Werror is annoying and not  very useful most of the time.

Signed-off-by: Niko Rosvall <niko@ideabyte.net>