ainvs: clean up and arch split BCorres

RISCV64 will need slight variations in the arch dependent proofs

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

SELFOUR-421: fix coding style

x64 invariants: reorder imports so that Include_AI comes before BCorres_AI

This makes forM_x and "crunch ignore" rules available to an arch-specific
crunch in BCorres_AI.

word_lib: adjust theory dependencies

lib/spec/proof/tools: fix word change fallout

arch_split: replaced sublocale with global_naming

arch_split: added ARM_A and ARM_H locales

arch_split: checkpoint. Checks up to ArchVSpace_AI with two sorries (MattB WIP)

arch_split: More namespacing progress and invariant splitting. Checks halfway into Invariants_AI