Fixed real/imag backwards bug in corr_snap

Also added bits and pieces for parsing antenna config file
Merge branch 'master' of https://github.com/jack-h/ami_correlator_sw
Aesthetic changes to printing of h5 file history

Print each history entry on a new line
Added a h5 preprocessing script

To zap the most terrible RFI, divide out autocorr bandpasses from
cross-corrs, and slice out bandpass edges
Added option to flip real/imag data parts

To cope with dodgy old data files