www/trac-batchmodify: set for deprecation

Mark as deprecated. Functionality of this plugin was merged into
Track since version 1.0. Set expiration date to 2015-04-08.

References:

• http://trac.edgewall.org/ticket/525
• http://trac-hacks.org/wiki/BatchModifyPlugin

PR: 197822
Submitted by: Anton Törnqvist <antont@inbox.lv>