Fix some compatibility issues

[mforets]

Closes #104.

[yuyichao]

Lgtm as long as 0.6 is still working. (It doesn't seem that this is a complete fix). Should be able to handle with compact if not working already.

[mforets]

Lgtm as long as 0.6 is still working.

The tests in v0.6 now pass locally.

It doesn't seem that this is a complete fix

True. I just fixed some more, but tests in v1.0.2 do not yet pass.
FWIW, the error is:

$ julia1 --color=yes test/runtests.jl
ERROR: LoadError: LoadError: Data mismatch reading logical_mat from logical.mat (v6)

Got Base.ReinterpretArray{Bool,2,UInt8,Array{UInt8,2}}:

Bool[true false false; false true false; true false false]

Expected Array{Bool,2}:

Bool[true false false; false true false; true false false]

I don't plan to send a new commit; I guess it is related to these lines in @halleysfifthinc's PR, but i haven't checked.

[yuyichao]

It doesn't seem that this is a complete fix

That's only relevant for 0.6 compatibility. Not a complete fix isn't a problem at all. No need to put everything in. I can merge as long as CI on 0.6 pass. Feel free to ping. (Not gonna watch it....)