Conversion to hdf5 without Merlin .hdr file

If no header file assume format of Merlin binary file newest and get colour mode version from binary header. If header file get format version from header file and get colour mode from header file. This was originally deemed necessary to facilitate conversion of Merlin binary files without a separate header file in cases where this would be confusing (e.g. when one of the experimental parameters was the counting threshold as in a threshold scan).

Doing this uncovered some issues when converting data acquired with a Medipix3 with a non-standard number of pixels (e.g. 128x128 pixels) and when using a Medipix3 detector in a less commonly used operational modes (e.g. Colour CSM).Data acquired in all modes of operation and with any number of pixels should now be converted correctly whether or not a separate header file is used in the conversion or not.