Standardize the return values where possible. (Currently some functions return a zero int for success and some for failure.) Add two new types: picolResult and picolBool. Have Picol commands return picolResult. Rename picolValidPtrAdd() to picolValidPtr(). 
Standardize the return values where possible. (Currently some functions return a zero int for success and some for failure.) Add two new types: picolResult and picolBool. Have Picol commands return picolResult. Rename picolValidPtrAdd() to picolValidPtr(). 

dbohdan/picol