stablerange: introduce ondisk caching through sqlite There is many short cut and limitation with this first version of a cache but this allow use to envision some actual usage of the stablerange thingy so let us got for it.

stablerange: drop the cache on 'destroyed' if the repository have been strip, the cache is not usable as is. We could be smarter in the invalidation but that is a prototype anyway. G: changed hgext3rd/evolve/stablerange.py

stablerange: support loading the cache iteratively We record how far we loaded so that we can resume from this point.

stablerange: add some basic documentation about the cache

stablerange: warmup all upto a revision Let us start doing more systemic warming of the cache before we start writing things out. This prepare on disk caching.

debugstablerange: add a --verify flag to the command This should help us finding bugs.

stablerange: add a proper debugstablerange commands This commands allows to inspect the standard stable range of a range. That should come handy.