XPath parsing support

[alcinnz]

For a project I'm working on I need to be able to evaluate user-provided xpaths.

I'm willing to implement an XPath parser myself upon xml-conduit Cursors, so would you be interested in accepting such a pull request?

[ivanperez-keera]

I'm also interested in this work. I need a mechanism to apply XPath to XML files, in Haskell. This library would be an option for me if XPath was supported.

[alcinnz]

I'll recommend using HXT for XPath.

I tried implementing a fix for this issue myself, but I found that XML-Conduit's datamodel is poorly-matched to XPath.

I'm tempted to close this issue since this isn't an issue for me anymore.