fetch: fix and document exit codes (issue2356)

doc: add [format] dotencode description

filectx: use ctx.size comparisons to speed up ctx.cmp Comparing sizes is cheaper than comparing file contents, as it does not involve reading the file on disk or from the filelog. It is however not always possible: some extensions, or encode filters, change data when extracting it to the working directory.

localrepo: use propertycaches to access encode/decode filters

localrepo: load filter patterns outside of _filter

localrepo: have _loadfilter return the loaded filter patterns

merge with mpm

wireproto/http: drain the incoming bundle in case of errors

wireproto: introduce pusherr() to deal with "unsynced changes" error The behaviour between http and ssh still differ: - the "unsynced changes" is seen as a remote output in the http cases - but it is correctly seen as a push error for ssh

wireproto: redirect the output earlier