new branch for ipi domain issue
fixed ipi issue for simple example Cdc42_ppi_Ste20; ! Ste20_[KD]--[CRIB2] \n Ste20_[KD]_ipi_Ste20_[CRIB2] and Cdc42_ppi_Ste20; x Ste20_[KD]--[CRIB2] \n Ste20_[KD]_ipi_Ste20_[CRIB2] domains are correctly shown. added also Intraprotein ot get_required_state so that we get ipi states here
tested Ste20_[KD]_ipi_Ste20_[CRIB2]; ! A--Ste20 and Cdc42_ppi_Ste20; ! Cdc42_[Gnp]-{P}; ! Ste20_[KD]--[CRIB2] both are valid
make some smaller changes to apply_positive_intraprotein. all tests are passing
added test for ipi dependent reaction