Merge branch 'release/0.45' into develop
iter_times now automatically calls __exit__ on grids when the iteration has finished
slicing vector fields now works correctly
implement curl
add iter_fields
small kwargs fixes
mayavi: wrap simple line plotting
better spilling
add some scratch to benchmark cython streamline tracing against fortran
play with tracing benchmarks
add compare operators to field type
allow iterating over named fields
p2d: more straight forward output behavior

-> -a sets the temp file prefix from the -a option
-> if no prefix, then set show to true, cause why else was it called...
implement lazy coordinates
give shape and dtype back to h5py data wrapper
cython streamlines are now almost fortran fast
print status when calculating streamlines
kwargs in field contructor gets passed to info dict
\n before time suptitle b/c quicktime has overlay window deco
fix xdmf reader bugs for reading PSC files