PomEditor: handle import-scope pom-type dependencies, too

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Add the "bump" mojo

Its purpose is to help SciJava projects maintain parent POMs, i.e. POMs
listing projects' current versions.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
WIP: debugging