add PYTHON_LDFLAGS and use python$(PYTHON_VERSION)-config for it and PYTHON_INCLUDE
Merge branch 'master' of github.com:sam-s/vowpal_wabbit
Merge pull request #417 from sam-s/master

improve python build portability
fixed version safety fail on 0-length versions
Merge pull request #418 from KaiWeiChang/SearchDepParser

a dependency parser
Labeled dep parser (current version is slow.....)