[Feature] Implement ICO methods

The release of the NEX ICO Template introduces several handy methods that are interesting. Specifically,the crowdsale handling methods that allow the client to check if the sales is active and if the address is whitelisted.

While this set of methods are not an official standard, the rise of contracts following these set of standard has been increasing and it is beneficial to include them as part of the API offering.

Specifics

• Comb through the NEX ICO template and find the methods to implement. Focus on methods that are useful from a client perspective (what methods are useful for a light wallet?)
• These methods are to belong in the api/crowdsale.js file.

References

• The methods you are crafting are probably similar to what is found in api/nep5.js

[snowypowers]

I have just read through the Orbis Contract and while it is nice that they are using C#, there is now a difference in methods:

Python:

crowdsale_status returns a boolean or a integer depending on whether have you contributed. crowdsale_available returns an integer

C#:

checkKYC is the equivalent of crowdsale_status but returns strings ‘on’ or ‘off’ C# does not offer the crowdsale_available equivalent

[jeroenptrs]

@snowypowers so there are three functions that seem interesting to me, two of which are crowdsale related and the other is mintTokens:

• crowdsale_status: gets the KYC Status of an address
• crowdsale_available: the amount of tokens left for sale in the crowdsale
• mintTokens: is this already implemented? Exchange NEO/GAS for the token

This one is more general, but seems interesting to add as well:

• circulation: the total amount of tokens in circulation

The rest are token owner functions