OpenSystemsDevelopment / qpdf

Eliminate the use of shared pointers in JSONParser

Reduce boilerplate and increase efficiency by avoiding setting and
branching on action and ready in getToken.

Also, reject them in strings.

Handle all incomplete token type errors in tokenError.

(except '\\' and '\uXXXX')

Reflect that the ls_number case only handles the digits after an 'e'.

Also, change state to ls_number for all 'ready' numbers.

Also, allow 'E' as alternative to 'e'.

Also. remove '.' as  starting char in lsTop.