licenses: convert license tags to SPDX

global: isabelle update_cartouches

lib: update for Isabelle 2019

lib+sysinit: add extended separation algebra and forward reasoning tactics

Added Extended Separation Algebra, which contains septraction and
separating coimplication.
Added Sep_Forward which contains tactics for reasoning forwards in
separation logic, updated sep_cancel.
Updated SysInit proofs.

Isabelle2018: new "op x" syntax; now is "(x)"

(result of "isabelle update_op -m <dir>")

Isabelle2018: new comment syntax

(result of "isabelle update_comments <dirs>")

globally use session-qualified imports; add Lib session

Session-qualified imports will be required for Isabelle2018 and help clarify
the structure of sessions in the build tree.

This commit mainly adds a new set of sessions for lib/, including a Lib
session that includes most theories in lib/ and a few separate sessions for
parts that have dependencies beyond CParser or are separate AFP sessions.
The group "lib" collects all lib/ sessions.

As a consequence, other theories should use lib/ theories by session name,
not by path, which in turns means spec and proof sessions should also refer
to each other by session name, not path, to avoid duplicate theory errors in
theory merges later.

Removes all trailing whitespaces

Isabelle2016-1: reorder imports to avoid the new Pure simplifier

Isabelle2016-1: update references to renamed constants and facts

sep_algebra: cleanup

- fixed legacy warnings
- fixed almost all other warnings as well
- clarified some monoid lemmas that had misleading mixed notation
- improved layout style compliance (seriously, people..)
- comment typo fixes etc

lib/sep_algebra: 2015 update

some of the global Isabelle2014 renames

option_case -> case_option
sum_case -> case_sum
prod_case -> case_prod
Option.set -> set_option
Option.map -> map_option
option_rel -> rel_option
list_all2_def -> list_all2_iff
map.simps -> list.map
tl.simps -> list.sel(2-3)
the.simps -> option.sel

release cleanup

Import release snapshot.