Add couch_httpd_misc_handlers:handle_file_req
Add couch_httpd_misc_handlers:handle_file_req

This can be used to serve up files like /crossdomain.xml from a
CouchDB instance. For example, you could add:

    [httpd_global_handlers]
    crossdomain.xml = {couch_httpd_misc_handlers, handle_file_req, "/usr/share/couchdb/www/crossdomain.xml" }

To your local.ini to serve up crossdomain.xml.

Closes #4

fkaempfer/couchdb,fkaempfer/couchdb,fkaempfer/couchdb,fkaempfer/couchdb,fkaempfer/couchdb,fkaempfer/couchdb