configure: check for boost -mt libs 

sometimes only the multi-threading libs are installed, which causes linking to the standard libs (without `-mt` suffix) to die..

in that case we might need something like this
```
LIBS="$LIBS -lboost_regex-mt -lboost_program_options-mt -lboost_filesystem-mt -lboost_system-mt -lboost_iostreams-mt -lz" 
```