Makefiles: Slight portability improvements for SWIG, add valgrind support
- Better handling of $SWIG_JAVA_PACKAGE
- $CFLAGS now passed to the linker when making SWIG extensions
- Makefile: Allow SWIG_*FLAGS to be overridden
  This will presumably happen for anyone trying to build SWIG extensions
  on a different distribution.
- new targets for valgrinding Python SWIG extensions and parseIt
  (JVM and valgrind don't get along so no target for this)
Minor attempts to reduce memory leaks
- parseIt: delete SentReps and charts under more circumstances
- */wrapper.i: more %newobject incantations
- simple-api.*: char* -> string in a couple cases

According to valgrind, there are still many major memory leaks so these
changes really only scratch the surface.
parseIt: always print LM scores when in LM mode
Not clear why it was only showing 1 in 10 of them previously.
first-stage/README: Minor updates and corrections.
Thanks to Matt Lease for noticing the language modeling problems!