TLR scheme works

reorginize TLNR

fix bug in TLNR

multistage works

fix the problem with recompute()

two level without revolve works for all the four modes

revolve online and offline work with solution_only on and off

revolve online works

revolve online and offline work

fix test cases for checkpoiting

ts->total_steps needs to be reset after recompute

fix pointer when freeing it

remove redundant declaration

first try to make the code more readable, compiles now

debugging 1

refactor code

fix compile errors

merge nek-style checkpointing here mannually

refactor the code to prepare for all the three versions of revolve

fix brackets and names

remove some whitespaces

adjust the scope of revolve macro

revolve configuration works

use macro PETSC_HAVE_REVOLVE

remove revolve sources files from PETSc