The pageerror option specifies the default page-level error handler
used by the error module. Page-level errors include all runtime errors that
occur during the processing of a Spyce (i.e. after the compilation phase has
completed successfully). This option can take one of two forms: 1)
"string:module:variable", where string is a literal,
module specifies a module in the server path and variable is the
name of a variable containing the default error template Spyce string; or 2)
"file:filename", where file is a literal and filename is the
name of the Spyce file to use as the default error template. The default value
for this option is "string:error:defaultErrorTemplate". Please refer to this
string in the error module to see how to define your own page-level error
handlers.