Inherit from pom-scijava

This eliminates several build warnings, and reduces the size of the POM,
since we no longer need to specify common sections which are already
defined in the parent.
Update organization to more general URL

OME is a major partner in SCIFIO development and holds copyright, but
SCIFIO has its own toplevel URL now to avoid the impression that SCIFIO
is a microscopy-specific project.
Remove picUrl property

The maven-site-plugin seems to ignore it, so it is rather useless.
Add back license-maven-plugin configuration
Remove tabs
Update license blurbs using license-maven-plugin