bump pom.xml versions to 2.5.1

Change-Id: I00599828dc2e98ec8d8ff0f6e8d0b2720ac1efbf
Review-Link: https://gwt-review.googlesource.com/#/c/2140/

Review by: skybrian@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@11544 8db76d5a-ed1c-0410-87a9-c151d255dfc7
3 files changed