build: Update to findbugs 3

Ensures Java 8 compatibility.

The patch also adds/corrects various pieces of meta data in the pom.

Target: trunk
Require-notes: no
Require-book: no
Request: 2.10
Request: 2.9
Request: 2.8
Request: 2.7
Request: 2.6
Acked-by: Paul Millar <paul.millar@desy.de>
Acked-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
(cherry picked from commit 507c3fced23220dbd6a203bc2d4a1e126e67d28f)

Conflicts:
	pom.xml

(cherry picked from commit 7a2013d10244442ae6b286585bbafa0a498aa171)

Conflicts:
	pom.xml
Merge pull request #788 from gbehrmann/fix/2.6/rb7206

build: Update to findbugs 3