REGEN: projects doc
REFACTOR: remove cachable paks (me-docstyle)
CLEAN: disable legacy mode by default.
REFACTOR: for pak 0.10
FIX: CPU spin for incomplete requests.
FIX: Socket reuse.

Add SO_EXCLUSIVEADDRUSE for windows and SO_REUSEPORT for linux.
CLEAN: unify SSL stack handling of buffered data.
CLEAN: change unit test actions to not use legacy mode.