[ANNOUNCE] urbit-os-v1.0.75

[phi...@tlon.io]

urbit-os-v1.0.75

You MUST receive this update if you wish to migrate your data across the
upcoming breach.

This release will be pushed to the network as an over-the-air update.

Base hash (check with +trouble):

0v1f.lbtqc.5o909.qqja6.17dgp.m8gde.bmiqc.fa97p.8jer8.msu43.5rf36

Release Notes:

* Add export functionality for all landscape apps. This will be used by the
flagday script to migrate your data across the breach.

* More correct behavior around leaving groups

Contributions:

Brendan Hay (1):
arvo: run %lens when lite boot (-l) is specified

Isaac Visintainer (27):
herb/lens: add utilites for import/export
aqua: manage azimuth state within aqua itself rather than using a thread
aqua: update and add new generators
ph: add and modify some ph helper functions; adds new thread for booting/breaching in the new paradigm, as well as a helper thread for just starting drivers in case you want to manipulate aqua manually
Merge pull request #4042 from urbit/ixv/aqua-azimuth
userspace: data migration testing utilities
groups: import/export
metadaa: import/export
contacts: import/export
invites: import/export
chat: import/export
graphs: import-export
herb/lens: add utilites for import/export
herb: expect * rather than @
userspace: data migration testing utilities
groups: import/export
metadata: import/export
contacts: import/export
invites: import/export
chat: import/export
graphs: import-export
graph-store: leave try-rejoin wire when subscription succeeds
apps: reorder maps, sets, and jugs
apps: reorder maps, sets, and jugs
Merge branch 'ixv/data-migration-with-lens' into ixv/data-migration
chat-hook: fix poke-import issue
chat-hook: fix another poke-import issue

Joe Bryan (6):
Merge branch 'master' into release/next-vere
Merge branch 'release/next-vere' into jb/restore-treap-jets
test: adds +find regression test, fixes set/map comment typo
Merge branch 'master' into release/next-vere
test: fixes +to-wain (no more trailing empty lines)
zuse: change to ropsten

Logan Allen (13):
observe-hook: add new thread to leave graphs upon removing a group
thread: %group-leave-graph now compiles
observe-hook: compiles
leave-graph: emit %done upon failed poke-acks
observe-hook + thread: remove metadata when leaving a group
contact-view: remove (now) unnecessary metadata removal
threads: collapse them into a single %group-on-leave thread
observe-hook: state-2 typo
thread: remove group-leave-metadata
%group-on-leave thread: simplified and got it to compile
group-on-leave: poke %graph-pull-hook to allow resubscription
group-on-leave thread: clean up contacts as well as everything else
Merge branch 'release/next-userspace' into la/archive-graph-on-leave

Philip Monk (6):
Merge remote-tracking branch 'origin/ixv/data-migration-with-lens' into m/flagday-keyfile
Merge commit '257b17bdf' into HEAD
lens: fix change lost in merge
kiln: add base-hash and our scries
Merge remote-tracking branch 'origin/ixv/data-migration' into philip/testnet-master
kiln: produce one base-hash via scry

fang (2):
Merge branch 'master' into release/next-vere
jael: add %vile scry endpoint for current keyfile