Like wanacot said, the feeling of love is relevant. I would venture to say that not only is it relevant to each individual, it is relevant to each relationship and perhaps it can change with age and experience.
Think of it in terms of a young boy, age 15 - 18 in his first long term committed relationship. He dates a girl for over 8+ months, lets say, and he initiates the back and forth of "I love you". Would the same experience and feeling occur in that same man at age 30 with a different lover? I would tend to think not.
Now I tend to think you have posted this question here, and please pardon me if I am incorrect, because someone may have recently confessed their love to you. Or perhaps a friend is going through an experience and you discussed it with them. Regardless, probably the most important indicator of the meaning of love is how it is acted upon by both people in the relationship. Talking about the emotions between you, what they mean, and how they reflect upon each individuals values within the relationship will tell you more about what a man means when he says I love you than anyone else can on this website.
Love can mean all of the things you mentioned in your question, and it can mean something entirely different. It's a feeling, an emotion, an action, reaction, and so much more. It's universally recognized, in that cultural references to love stimulate our "hearts" and "minds" to recognize with it.
This question reminds me of a scene from waking life. A woman sitting at a bar with main character (who is lucid in his dreams) states "When I say "love," the sound comes out of my mouth and it hits the other person's ear, travels through this Byzantine conduit in their brain, you know, through their memories of love or lack of love, and they register what I'm saying and they say yes, they understand. But how do I know they understand?" You see, when you think of love, and when I think of love, we can both sit and talk about the butterflies, what it means to us, how we have expressed it, and what love looks like for us. But when it comes down to understanding the emotion, we both have to rely on our own experiences of love - which makes it unique.
When a gentleman says he loves you, he means he more than likes you. Hah, that is about all I can conclude. I can tell you what it means for me, but that would not be universal of all men.