Fix issue #249

[lohedges]

This PR closes #249 and OpenBioSim/somd2#60.

• I confirm that I have merged the latest version of devel into this branch before issuing this pull request (e.g. by running git pull origin devel): [y]
• I confirm that I have added a changelog entry to the changelog (we will add a link to this PR as part of the review): [y]
• I confirm that I have permission to release this code under the GPL3 license: [y]

[chryswoods]

Thanks for catching this - looks great :-)

[lohedges]

No problem. It's one of those where you wonder how it ever worked in the first place. It's also quite surprising (and dangerous) that QByteArray appears to be one of the few Qt data structures that doesn't have an aliased .count() method, i.e. as an alias for .size(). I find it so easy to use .count() by mistake since I'm used to using it for QVector and QList, etc. Perhaps we should be careful to use .size() throughout in future.

I've just pushed a minor update to increase the wait period before terminating QThread objects when cleaning the PageCache. On my machine, this stops the random FATAL: exception not rethrown seen on interpreter exit, although it might not be a 100% reliable solution on all platforms. (I also didn't see any crashes if I just commented this part of the code, i.e. didn't attempt to wait for threads to stop at all.)

[chryswoods]

I agree about size versus count, but this is so ingrained in my subconscious that the change would be difficult... ;-)