Fix tests on 32 bit platforms

[klao]

The library was failing tests on my 32 bits machine.

Two tests were failing:

1. prop_showRead :: Day -> Bool. This is just because Day in Int64 internally and YearMonthDay has an Int as year. I limited the range of Days we test to Int.
2. prop_parseTime. This is a real bug; you were parsing '%s' as an Int, which introduced a year 2038 bug to your code.

We did the debugging together with @errge.

[liyang]

I've pushed the part of that commit fixing the "%s" parsing in e2c96e6.

Trying to figure out if there are reasonable Bounded instances for YearMonthDay & UTCTime &c. (and reduce the range of the existing instance Bounded Day), such that all conversions between the assorted types do not overflow. I'm trying to avoid #ifdefs on word size... maybe that's not practical.

Perhaps the instance Arbitrarys should go into the library proper, since QuickCheck is already in the platform.

[errge]

Yes, this definitely fixed that issue, as can be seen in this build log:
https://api.travis-ci.org/jobs/10855175/log.txt?deansi=true

Thanks!

[liyang]

I'm working on getting the instance Arbitrarys into the library right now, and will release when I'm done, hopefully within a few days.

[errge]

https://travis-ci.org/errge/thyme/builds/11008259

The recent git commits make thyme build and test cleanly on both amd64 and i386 with GHC 7.6.3. I haven't tested other configurations.

[liyang]

I believe b88dc1e and 9bae6a0 (and I guess 4698e21) fixed the remaining issues. Thyme is now officially not Y294K-compliant, although we just need to switch the epoch from that of the MJD to fix that one, or move to 128-bit words…