Fix mantis 2883

update hud_num_make_mono (& callers) to handle the font number
add partial support for specifying special char indexes for individual fonts

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@9985 387891d4-d844-0410-90c0-e4c51a9137d3
Fix mantis 2889: add sexps's ets-get-value & ets-set-values

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@9986 387891d4-d844-0410-90c0-e4c51a9137d3