Update train-model.perl

When I was working with factored models, my experiments failed. After some invistigation, I discovered that the delimiter is hardcoded in several places to "|" so I changed it to $___FACTOR_DELIMITER
use boost::unordered_map for CacheColl. Marginally faster
fix bug if interpolated lm on different factors
Merge branch 'master' of ssh://github.com/moses-smt/mosesdecoder
copy weights of features with 'tuneable=false' to final config (now also works with -return-best-dev)
tune DALMWrapper.
improve DALMwrapper.
Merge pull request #59 from akholy/master

Update train-model.perl
modify DALMwrapper.
Merge branch 'master' into fscorer