Log Message:
Update tex-l3{experimental,kernel,packages}{,-doc} to 0.5700

Snapshot of SVN 5700
====================

  - Fix issue which prevents expl3 loading with (u)p-TeX
  - Fix issues with key path parsing by l3keys
  - Fix galley interaction with \vtop and similar
  - Documentation improvements

Note that the team are looking at more formalised (u)p-TeX
support: this fix maintains the abilty of expl3 to work
with these engines without formal support.

Snapshot of SVN 5666
=====================

 - Update l3keys such that key properties are additive,
   introducing a new .undefine: property to support this
   and altering .value_forbidden:/.value_required: to
   .value_forbidden:n/.value_required:n

 - Fix detokenization of key names in some parts of l3keys

 - Update to l3keys2e to correctly find key names following
   l3keys fix

 - Fix extraction of \l_keys_key_tl from \l_keys_path_tl

 - Update case changing data for Unicode 8.0.0

 - Reintroduce minimal LuaTeX-specific functions as l3luatex

 - Remove function deprecated during 2012 and 2013

 - Extend saving of primitive (\<engine>_<name>:D)
   to cover all XeTeX and LuaTeX names including
   those for Unicode math handling