Fixed some warnings

[essenciary]

Fixed a series of deprecation warnings in Julia 0.5

[iamed2]

This is going to need more detailed attention in order to keep compatibility with 0.4

[essenciary]

It's a bit of a mess - the last 2 commits were about switching back to bytestring() as unsafe_string() would make the tests to fail (it's not a straightforward replacement).

420272a and 2c4ac45 are all right.

I can tweak them a bit, to keep them working in v0.4. I'm thinking by adding version detection and type / function aliases?

Or if you have other ideas, let me know, happy to help.

[iamed2]

Version detection with aliases sounds like the right way forward to me :)

[essenciary]

All right, I'll give it a go 👍