Removed an unused IQTensor constructor.
Removed jth IQTensor index accessor (because tensor interface shouldn't depend on index order). Updated last few parts of the code still using it.
Added print (<<) support for Spectrum objects. Lots of work on experimental tevol code. Mostly simplified and cleaned up code related to grouping and ungrouping pairs of sites before and after time steps.
Fixed erroneous check in ITensor::isZero.
Added debug check to IQTensor::operator+=(ITensor) which checks that block being added has the same divergence as the IQTensor. Changed signature of IQTensor::conj to return a reference to *this.
Added backwards compatibility wrapper around new DerivMPS function object.
Fixed addition of incompatible block to an IQTensor in svdalgs unit test. Wrote corresponding unit test for IQTensor.
Restored lines scaling real and imag part to same scale fac in svdRank2, fixing a potential bug. Added a refinement that avoids making U and V blocks complex when imag part is actually zero.
Fixed buggy IQTSparse unit test defaults struct which created IQTensors with QN-inconsistent blocks.