Log Message:
mail/dovecot2-pigeonhole: distfile changes

Distfile changes.

1. Official annoucne says "The only change here is that the configure.ac
   file has correctly formatted version number."

2. Name of distfile is changed to match previous file naming scheme.
   Old distfile is still available.

3. automake 1.15.1 is used instead of previous 1.15.  So, generated files
   by it are changed.

4. Other files are not changed, so there is no functional change.

Bump PKGREVISION.