Copy dvBinding.node to lib, so "node-gyp clean" can be used without worries.

This change should be helpful when putting node-dv inside a docker container.
Update copyright.
"node-gyp clean" as postinstall.
Version bump to 1.6.2.
Sync .npmignore with .gitignore.
remove NULL assertion in pageiterator as in svn878
add tesseract variable accessors
Unbreak windows build.
Ignore *.bak and core dumps.
Display correct error message when arguments can't be converted in Tesseract#findText().
Version bump to 1.7.0.
Ignoring "core" was a bad idea.
Version bump to 1.7.1.
Fix non-ascii variable issues.
Version bump to 1.7.2.
Add contributor, add some keywords, fix some typos.
Added Image#lineSegments() and Image#drawLine().
Added OpenCV and LSWMS.
More parameters for Image#LineSegments() and Image#DrawLine().
Merge branch 'master' into tesseract303