Large Numbers as strings

[schmidtw]

I wanted to see if there would be any interest in accepting a patch where large numbers (like even larger than 64bit numbers) would be handled as a string in addition to a native type, or if large enough, just a string.

Why strings?

• While generally not ideal for numbers, it's pretty easy to represent a 64 byte number as a string. The code that needs to handle the crazy number can deal with it vs. cJSON needing to.
• Allows software that want 64bit number support to add it & deal with it outside cJSON while allowing cJSON to stay C89.
• It looks like it would be pretty easy to add to the decoder (like a cJSON_strdup() call into item->valuestring)
• I don't want to change code away from this library that is really solid just because I need to pass large numbers in a few specialized payloads (& that can't string encode them...)

[schmidtw]

I went an wrote up what I had in mind & got the tests working as well. https://github.com/DaveGamble/cJSON/pull/580

[schmidtw]

@Alanscut what do you think about this approach?