[PATCH 00 of 19] mq and locking

[Mads Kiilerich]

A mq hacking session ended up with this bunch of more or less related patches.
They have varying degree of dependencies, so some of them might apply even
though previous patches has been skipped. Please review carefully and pick what
you like.

My primary goal was to make sure that mq used locking properly. The theory was
that incorrect locking caused TortoiseHg to observe inconsistent repository/mq data.
Improved locking did however not make much difference. The mq data are not
append only and can't be updated atomically, so the usual scheme with unlocked
readers doesn't work ... especially not when repository stripping is involved.

/Mads