Various improvements

[timholy]

This adds various performance and usability enhancements (fixes #16, at least the parts that can be fixed).

It also eliminates the deprecations; I think we've had those long enough that anyone relying on the old behavior has had long enough to fix problems.

[timholy]

@alsam, can you please enable attobot? It only takes a couple of moments to activate it (https://github.com/attobot/attobot#usage), and it saves me some hassle.

[timholy]

(If you do the next release, I think it should be v0.3.0 since I deleted some deprecations.)

[timholy]

@alsam, any interest in moving this to JuliaArrays? I can set you up with the necessary permissions if you like that idea.

Meanwhile, I'll go ahead and tag 0.3.0 the old-fashioned way.

[alsam]

Sure @timholy, it is great idea to move the library to https://github.com/JuliaArrrays , I like it. Could you please set me up with permissions?
Thank you!

[timholy]

OK, done. I'm a little confused about what privileges are needed to transfer ownership; if you find you can't do it, then let me know and I'll try to fix it.

[alsam]

Thank you! Just joined JuliaArrays organization taking advantage of your kind invitation.

[alsam]

@timholy I've just imported from https://github.com/alsam/OffsetArrays.jl to https://github.com/JuliaArrays/OffsetArrays.jl No problems with permissions so far.
Let me know if something has to be done with the new repository.

[alsam]

@timholy just killed https://github.com/JuliaArrays/OffsetArrays.jl - details are here JuliaLang/METADATA.jl#8884
could you please add admin rights for "Transfer repository" or move it yourself? Thanks!

[timholy]

OK, try the transfer again. Sorry about the inconvenience.

[alsam]

Thank you. No problem. I've finished transfer. Could you please check if it has right access rights for you?

[timholy]

Yep, looks good! Coupled with @Evizero's PR here, we're all set. Many thanks!

[Evizero]

I am unsure, but it may be needed that someone with admin permission enables Travis under JuliaArrays (?)

[timholy]

Thanks for noticing, I checked and we see to be OK.