Appends string.
Returns new string length.
strappend[param, s]
#<str> = "PlanetCNC" #<len> = strappend[#<str>, " Rocks"] (print,#<str>)
Output: PlanetCNC Rocks
#<str> = "PlanetCNC" #<str2> = " Rocks" #<len> = strappend[#<str>, #<str2>] (print,#<str>)
Output: PlanetCNC Rocks
#<posx> = "X: " #<posy> = "Y: " #<len> = strappend[#<posx>, #<_x>] #<len> = strappend[#<posy>, #<_y>] (print,#<posx>, #<posy>)
Output: X: 12.34, Y: 45.78
#<ss> = 5 o<chk> if[#<ss> LT 10] #<ssstr> = "0" o<chk> else #<ssstr> = "" o<chk> endif #<len> = [strappend[#<ssstr>, #<ss>]] (print,#<ssstr>)
Output: 05