String Conversion Opcodes

These opcodes convert string variables (note: most of the opcodes run at init time only, and have a version with a "k" suffix that runs at both init and performance time; exceptions to this rule include puts and strget):

• strtod and strtodk - Converts string value to a floating point value at i-rate.
• strtol and strtolk - Converts string value to signed integer at i-rate.
• strchar and strchark - Returns the ASCII code of a character in a string.
• strlower and strlowerk - Converts a string to lower case.
• strupper and strupperk - Converts a string to upper case.