doc: remove obsolete GAPDoc comments

Instead, add comments which point to the actual documentation.
doc: rewrap documentation strings, first step towards readability
doc: fix some typos in the manual
doc: Change mentions of CreateAutoDoc to CreateAutomaticDocumentation
doc: more cleanup
doc: major overhaul of the documentation

This removes most of the repetition in the manual, which makes maintenance
easier, and also helps user who now have a much easier time to spot the
differences between the various AutoDoc functions.

The readability of both the documentation source as well as of the
generated manual is also improved.
doc: move Declare* funcs into separate section
doc: regenerate documentation
doc: avoid emitting empty func labels
Merge branch 'docu-fixes' of https://github.com/fingolfin/AutoDoc

* 'docu-fixes' of https://github.com/fingolfin/AutoDoc:
  doc: avoid emitting empty func labels
  doc: regenerate documentation
  doc: move Declare* funcs into separate section
  doc: major overhaul of the documentation
  doc: more cleanup
  doc: Change mentions of CreateAutoDoc to CreateAutomaticDocumentation
  doc: fix some typos in the manual
  doc: rewrap documentation strings, first step towards readability
  doc: remove obsolete GAPDoc comments

Conflicts:
	gap/AutoDocEntries.g
	gap/AutoDocMainFunction.gd
	gap/CreateDocumentationEntries.gd
	gap/DeclareWithDocumentation.gd