Bump all plugin versions to the newest ones

As found out by running "mvn versions:display-plugin-updates", described
in

http://blog.sonatype.com/2013/09/simplified-releases-to-the-central-repository-with-nexus/

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Remove maven.imagej.net entries from pom-scijava

... in preparation for deploying to OSS Sonatype (which does not
allow external references to random Maven repositories).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
pom-scijava: Add a profile for deploying to OSS Sonatype

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
pom-scijava: Add the OSS Sonatype repositories

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
White-space fix

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Add an <scm> section to pom-scijava, required by the release plugin

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Use the nexus-staging-maven-plugin for deploying

As described in

http://blog.sonatype.com/2013/09/simplified-releases-to-the-central-repository-with-nexus/

Unfortunately, the nexus-staging-maven plugin's version 1.5.1 requires
Maven 3.0.4 -- while we want to require 2.2.1 in general instead -- and it
is not possible to override the minimally-required Maven version in a
profile, not even by using a property in the <prerequisites> section. For
now, we just have to live with 'mvn versions:display-plugin-updates'
complaining about that...

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Fix release:prepare not committing the version into the tag

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
TO-UNDO