Mention ParameterHandler exceptions in changes.h.
Mention ParameterHandler exceptions in changes.h.

The last few commits change the behavior in an incompatible way by
raising exceptions on invalid input instead of using a return code.

EGP-CIG-REU/dealii,shakirbsm/dealii,JaeryunYim/dealii,naliboff/dealii,kalj/dealii,kalj/dealii,danshapero/dealii,spco/dealii,danshapero/dealii,danshapero/dealii,shakirbsm/dealii,JaeryunYim/dealii,EGP-CIG-REU/dealii,danshapero/dealii,sairajat/dealii,shakirbsm/dealii,sairajat/dealii,JaeryunYim/dealii,spco/dealii,sairajat/dealii,shakirbsm/dealii,sairajat/dealii,danshapero/dealii,EGP-CIG-REU/dealii,naliboff/dealii,naliboff/dealii,spco/dealii,sairajat/dealii,naliboff/dealii,danshapero/dealii,shakirbsm/dealii,JaeryunYim/dealii,shakirbsm/dealii,kalj/dealii,JaeryunYim/dealii,spco/dealii,EGP-CIG-REU/dealii,EGP-CIG-REU/dealii,spco/dealii,naliboff/dealii,spco/dealii,danshapero/dealii,sairajat/dealii,EGP-CIG-REU/dealii,kalj/dealii,kalj/dealii,spco/dealii,sairajat/dealii,naliboff/dealii,naliboff/dealii,kalj/dealii,JaeryunYim/dealii,shakirbsm/dealii,kalj/dealii,EGP-CIG-REU/dealii,JaeryunYim/dealii