When more than one hdf files are extraxted from the archive, sds are read from all, and possible errors (mostly due to hdfs containing no more than one sds) are handled
Made greps on vis case insensitive, since VI names are capitalised in the hdf subdatasets
Bumped up the version number of the package to 0.3
Merge branch 'hotfix-hdf'
Cleaned all the vignette junk