updated copyright statements and PETMR->SyneRBI

[KrisThielemans]

also occasional license

closes #660

[KrisThielemans]

As this changes so many files, I've now also updated the references to CCP PETMR.

sed script used:

s/CCP PETMR/SyneRBI/
s/CCPPETMR/SyneRBI/
s/Positron Emission Tomography and Magnetic Resonance imaging/Synergistic Reconstruction for Biomedical Imaging (formerly CCP PETMR)/
s#Synergistic Reconstruction for PET/MR#Synergistic Reconstruction for Biomedical Imaging (formerly CCP PETMR)#
s#www.ccppetmr.ac.uk#www.ccpsynerbi.ac.uk#

Used via

find ~/devel/SIRF/data \( -name .git -o -name data \) -prune -o -type f \
  sed -i -f ~/devel/renameCCP.sed {} \;