Also adjust the periods in Simulated_time_series (output of the perfect
foresight solver in the workspace). Note that this dseries object contains the
observations for the initial condition (M_.orig_maximum_lag observations) and
for the terminal condition (M_.orig_maximum_lead observations).
See #1838.
Fix testsuite (wrong file name)
Rename histval_initval_file/ramst_data.mod to ramst_data_generate.mod.
Otherwise, there is a conflict between the +ramst_data folder and the generated
ramst_data.m.
Similarily, rename shock_decomposition/shock_decomposition_backward.mod to
shock_decomposition/shock_decomp_backward.mod (otherwise it conflicts with
matlab/shock_decomposition_backward.m).
Several tests need to be adapted, because they were implicitly making the
assumption that there is no auxiliary variable.
Incidentally, this closes#1731. This commit therefore also removes the
workaround introduced in 0391dbbeb1.