Merge pull request #249 from hal3/master

fixed neighbor feature auditing, and affix feature storing in file
fix windows build issues
Fix AC_PATH on mac os x with homebrew
by default, homebrew installs into /usr/local, while the autoconfigure script looks in /opt/local for autotools. This commit tests for the existence of an /opt/local directory, then falls back onto /usr/local if none is found.
Merge pull request #250 from timcowlishaw/fix_mac_ac_path

Fix AC_PATH on mac os x with homebrew