v0.2.19

Added

• tetragono: Add a new command gm_hamiltonian to replace the Hamiltonian of the existent sampling lattice.
• tetragono: Add conjugate_gradient_method_error option for gm_run and mp_run in teragono shell. The conjugate
  gradient will stop if conjugate_gradient_method_step reached OR conjugate_gradient_method_error reached. Set
  conjugate_gradient_method_error to 0.0 to skip error checking or set conjugate_gradient_method_step to -1 to
  skip step checking.

Changed

• lazy: Using a manual stack to run the recursion now, to avoid the recursion depth limit.

Fixed

• tetragono: Fix a problem when calling gm_data_load in tetragono shell.
• tetragono: Fix a bug in calculating the natural gradient of a complex tensor network state.
• tetragono: Fix a bug in calculating the expect and the deviation in the ergodic sampling with subspace restricted.