Started PDE Schur
first attempt at lyap(SchurOperator)
Got cont_constrained_lyap(Schur) working
Added PDEOperatorSchur
PDEOperatorSchur \
Support for I
auto size rhs
precompute diags
c*PDEOperator and PDEOperator-PDEOperator
Support for forcing term (Bug: off by 2x)
Fixed ConstantOperator*Fun
Fixed PDEOperator+PDEOperator
Fixed bug in block backsub (there's still another bug...)
Fixed permute of columns
Merge pull request #11 from dlfivefifty/feature-PDESchur

Feature pde schur