Execution control

• sgs_XFCall - call variable as function
• sgs_XCall - call variable as function without this passed to it
• sgs_XThisCall - call variable as function function with this passed to it
• sgs_FCall - call variable as function
• sgs_Call - call variable as function without this passed to it
• sgs_ThisCall - call variable as function function with this passed to it
• sgs_GlobalCall - call a global function
• sgs_Abort - abort the execution of the previous SGS functions up to the last C function before them
• sgs_Cntl - set and/or retrieve various states in the system