* Added FileSelector interface.

* <v-fileset> now takes file selectors, instead of include and exclude patterns.

* Added a bunch of file selector implementations:
  * <and>, <or>, <not> for combining selectors.
  * <name>, <basename>, <url> for testing bits of the file name against
    an Ant 1 style pattern, or a regular expression.
  * <is-file>, <is-folder>, <exists> for testing file type.

* Added <flat-fileset>, which combines nested file sets and paths into a
  single directory.  This allows explicit path -> fileset conversion.

* Added <filtered-path>, which applies selectors to nested file sets and paths.

* Added <list-fileset> debug task.


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@271577 13f79535-47bb-0310-9956-ffa450edef68