
createv:
   usage: "createv <varname> <vartype> <format> <value> [strlen]"
A web variable that can be referenced within web files is created.  
* <varname> is the name of the variable
* <vartype> is the type of the variable (INT8, INT16, INT32, FLOAT32, 
  or STRING)
* <format> is the printf-style format specifier for outputting the 
  variable (such as "%d")
* <value> is the value to assign the variable.  
* [strlen] is only used if the variable is of type STRING.  It is
  used to give the maximum length of the string.
