(7 May 2020, @ankostis): superseded immediately BY v8.0.2 due to more restructs

--((superseded immediately BY v8.0.2 due to more restructs)))--

(7 May 2020, @ankostis): re-MODULE; sideffect --> sfx; all DIACRITIC Modifiers; invert "merge" meaning

• BREAK: restructured netop && network modules:

  • :mod:.network module was splitted into :mod:.execution which now
    contains plan+solution;
  • unified modules op + netop --> :mod.composition.
  • DOC: module dependencies diagram in :doc:reference.
  

• BREAK: sideffect modifier functions shortened to :func:.sfx & :func:.sfxed.

  • FEAT: +Sideffected :term:varargish -- now :term:sideffected fully mirror
    a regular dependency.
  • ENH: change visual repr\esentation of modifiers with DIACRITICS only.
  • refact(modifiers): use cstor matrix to combine modifier arguments; new utility
    method for renaming dependencies :func:.dep_renamed()
    (usefull when :ref:operation-nesting, see below).
  • ENH: possible to rename also sideffects; the actual sideffect string is now
    stored in the modifier.

• BREAK/ENH: invert ":term:merge <operation merging>" meaning with (newly introduced)
  ":term:"nest `"; default is now is merge:

  • FEAT: introduce the :class:NULL_OP operation that can "erase" an existing
    operation when merging pipelines.
  • ENH: compose(..., nest=nest_cb) where the callback accepts :class:.NestArgs
    and can perform any kind of renaming on data + operations before :term:combining pipelines <combine pipelines>.
  • doc: "merge" identically-named ops override each other, "nest" means they are prefixed,
    "combine" means both operations.
  • DOC: re-written a :ref:merge-vs-nest tutorial <operation-merging> for humanity.

• DROP(op): parent attribute is no longer maintained -- operation identity now
  based only on name, which may implicitly be nested by dots(.).

• ENH(plot): accept bare dictionary as theme overrides when plotting.

• doc: fix site configuration for using the standard <s5defs> include
  for colored/font-size sphinx roles.