store: move encode lambda logic into fncachestore and define two named functions at module scope. This again also speeds up perffncacheencode a little bit.

store: eliminate one level of lambda functions on _hybridencode

store: parameter path of _auxencode is now a list of strings

store: keep an accumulated length for the shorted dirs in _hybridencode so we don't have to repeatedly do '/'.join(sdirs) inside the loop

store: reorder basename assignment in _hybridencode

store: remove uneeded startswith('data/') checks in encodedir() and decodedir() I don't think we will ever have anything in the store that resides inside a directory that ends in .i or .d under store/ that we wouldn't want to have direncoded. The files not under data/ surely don't need direncoding, but it doesn't harm to let these few run through it. It hurts more to check whether the thousands of other files start with 'data/'. They do anyway. See also 810387f59696 (fixed with c31fe74a6633), which moved the direncoding from filelog into store