`getfieldInfo` can now also take a source index as argument. Plus it was modified to also handle "telem1+" etc.
New functions `getSourceIndex(sourceName)` and `getSourceName(sourceIndex)` were added, which use the names shown on the
screen instead of the special names table used by `getFieldInfo` and `getValue`.
Indices are the same for all of the functions, so `getValue(sourceIndex)` also works with indices from `getSourceIndex`.
New iterator functions `sources([first[, last]])` and `switches([first[, last]])` for getting ranges of sources and switches.
`getPhysicalSwitches` was removed, as I consider the iterator function to be a better solution.
