move everything to subfolder theories/

theories/prelude/tactics.v

theories/prelude/vector.v

theories/prelude/zmap.v

theories/program_logic/adequacy.v

theories/program_logic/ectx_language.v

theories/program_logic/ectx_lifting.v

theories/program_logic/ectxi_language.v

theories/program_logic/gen_heap.v

theories/program_logic/hoare.v

theories/program_logic/language.v

theories/program_logic/lifting.v

theories/program_logic/ownp.v

theories/program_logic/weakestpre.v

theories/proofmode/class_instances.v

theories/proofmode/classes.v

theories/proofmode/coq_tactics.v

theories/proofmode/environments.v

theories/proofmode/intro_patterns.v

theories/proofmode/notation.v

theories/proofmode/sel_patterns.v