add startswith function to xpath
api for supporting alternative node types for return (still need to document), and add untested implementations of the rest of the functions
xpath_str macro for more efficient usage, allow parsing and using any type of xpath expression, fix several bugs, and update readme
Merge branch 'jn-xpath-add' of git://github.com/vtjnash/LibExpat.jl into vtjnash-jn-xpath-add
fix find() xpath types, reduce number of unnecessary exports
Merge branch 'jn-xpath-add' of git://github.com/vtjnash/LibExpat.jl into vtjnash-jn-xpath-add