Real Property – Recovery of possession of land – Adverse possession – Whether deceased’s possession of land extinguished the title of the registered owner prior to the exercise of the mortgagee’s power of sale – Whether the purchaser from a mortgagee takes free of an unregistered possessory title – Purchaser in possession – Squatter – Whether agreement for sale in existence- Whether the deceased had the requisite animus possidendi where occupation commenced under incomplete agreement for sale – Acknowledgement of title –Burden of proof in a claim for recovery of possession where adverse pos