v0.3

Lots of new features in this release including:

• loading Siemens DICOM .IMA MRS files
• MRSData now has a sister class MRSSpectrum
• functions to adjust phase and frequency of spectra
• ability to get voxel position out of twix data
• DICOM MRI volumes can be loaded and registered
  with spectroscopy voxels
• improved parsing of Tarquin results
• significant improvements to the documentation