api => 2 rollout

[plicease]

New features:

• [x] pass array into pointer types #227
• [x] NULL is returned as undef instead of empty list
• [x] consider: rework string(length) types, which are internally is identical to record(length). In api => 1 this means that you use string(length)* instead of string(length) which is counter intuitive. Related: https://github.com/PerlFFI/FFI-Platypus/issues/340
• [x] document fixed length strings #340
• [x] ~better warnings on wrong types: https://github.com/PerlFFI/FFI-Platypus/issues/337~

Rollout steps required:

• [x] tests that test api 0 and api 1 should also test api 2
• [x] All internal code in lib should use api => 2 (eat our own dogfood)
• [x] Documentation should be updated to use FFI::Platypus 2.00 and api => 2.
• [x] During late dev run of 1.00 (1.9x), api => 2 should be allowed without experimental => 2 without warnings (No Prod version of 1.xx should allow this)
• [x] Release 2.00

[plicease]

* [ ]  consider: rework `string(length)` types, which are internally is identical to `record(length)`.  In api => 1 this means that you use `string(length)*` instead of `string(length)` which is counter intuitive.  Related: [Document fixed length strings #340](https://github.com/PerlFFI/FFI-Platypus/issues/340)

I think string(length) should just be an alias for string(length)*. record(length) should still be illegal.