Old routines moved to an obsolete folder
New solution routines implemented
explicit naming of 11 solution algorithms

for constant-parameter models:
- rise_1 : default for constant-parameter models
- klein,
- sims,
- aim
for switching parameter-models
-mfi : default for switching-parameter models
-mfi_full: mfi without exploitation of sparsity
-mnk: newton algo with kroneckers
-mnk_full: mnk without exploitation of sparsity
-mn: newton without kroneckers
-mn_full: mn without exploitation of sparsity
-fwz: Farmer, Waggoner, Zha (2011)
naming of the optimal policy solver