Added targets.py
New DOF. Beam utility stuff. Fixed srcdata slicing. Added pmat_model and other src utility things.
Merge branch 'master' of uio:git/repos/enlib
Some constants in utils
Fixed loss of array subtype in degrees of freedom
Allow specification of reference phi for 2pix
Incompatible change to enlib.wcs. Now much more flexible in how wcs objects can be constructed, for example by specifying a resolution. Also uses degrees now, like wcs does internally. enmap has been updated to handle the change. Added geometry to enmap, which propagates the new flexibility.