[lmi] building LMI with newer boost

[Vadim Zeitlin]

 Hello,

 I know and understand (and agree with) the reasons why LMI uses a frozen
version of Boost but so far I was using a version already installed on my
system for the MSVC builds. It was 1.34 and it worked just fine. Recently
however I installed 1.36 and now I have a problem with fs::path::has_leaf
which has disappeared in it. It was apparently a mistake and corrected
since then (see https://svn.boost.org/trac/boost/changeset/48374/) but
has_leaf() as well as leaf() and other functions using this word were
nevertheless deprecated in favour of has_filename(), filename() &c. So I
wonder if you'd agree to commit a workaround which would use the filename
functions instead of leaf ones if BOOST_VERSION >= 103600. I realize that
it probably isn't particularly useful to LMI right now but sooner or later
you will start using a more recent Boost version and it might be nice to
not have this problem then.

 Unfortunately I don't see any nice way to make this work with both the old
and new Boost versions. The least ugly would probably be to have functions
file_path_get_filename() or something like this which would use the check
for BOOST_VERSION above -- at least like this it would need to be done in a
single place only. OTOH has_leaf() is only used in 2 places right now (And
leaf() in a couple of more) so maybe inserting 2 #ifs right where it's used
is not too bad?

 Please let me know what do you think about this, thanks,
VZ