dirstatemap: arrange methods by category The dirstatemap code cover various aspects, it grow a bit messy over the years. So we shuffle the code around into some documented categories. This will help use to clean up the code. No code was changed in this changeset, only code move. Differential Revision: https://phab.mercurial-scm.org/D11568

dirstatemap: move a multiple simple functions in the common class These are small and simple, lets factor them out. Differential Revision: https://phab.mercurial-scm.org/D11567