Added operator* for IndexSets. Works similar to tensor contraction but on an index level only.
Renamed README and INSTALL to README.md and INSTALL.md since both use Markdown syntax.
Fixed incorrect method IndexSet::back().
Added support for contracting two Diag ITensors (as long as they share at least one common Index).
Added some checks to psiphi method to make it succeed in a broader set of cases.
Enhanced eigDecomp method to use indices of V if provided to request which indices to T to treat as row versus column.
Removed unused typedef from iqcombiner.h
Removed itsparse.h/cc and iqtsparse.h/cc
Added support for default operators to measure in Model classes.