[lmi] Let's avoid doxygen's markup language

[Greg Chicares]

I should have said this before, but let me say it now: I strongly
agree with David Abrahams's message cited below. We had only four
'@' characters in '///' comments, and I've removed them. Example:

- /// The default version of the method returns @c NULL indicating
+ /// The default version of the method returns NULL indicating

The fewer markup languages we have to learn, the better. If it's
necessary to quote a name, let's just use quotes, e.g.:
  /// Precondition: 'is' is an open std::ifstream.
instead of this:
  /// @pre @c is is an open std::ifstream.

  http://lists.boost.org/Archives/boost/2002/10/38746.php
| I hate weird junk in comments; From most of my code you could
| pick up exactly what to put in the docs with just the
| appropriate comment processor and no directives.
[...]
| > @param foo Description of the foo parameter
| > @param bar Description of the bar parameter
| > @return Description of the return value
| > @pre Precondition 1
| > @pre Precondition 2
| > @post Postcondition 1
| > @throws Exception commentary
|
| Yuck!
|
| That should be:
|
|         // foo - description of foo parameter
|         // bar - Description of the bar parameter
|         // Returns: Description of the return value
|         // Preconditions: Precondition 1; Precondition 2
|         // Postcondition: Postcondition 1
|         // Throws: Exception commentary
|
| *Now* you get the idea