Visualisation bug fixes.

Remove CSS :hover animations.

It's confusing to have the same attributes controlled both by Javascript
and CSS. Also the growing-node behaviour was unhelpful, because it
generally obscured arrow-heads, thereby hiding the direction of
relationships.

Delegate overlay shape to arrow objects.

Use a dedicated path object instead of rectangles so that we can detect
hovering over curved arrows.

Improve contract between layout and arrows.

Previously we set an additional shortCaptionLength property on arrow
objects after instantiation. Instead we supply that value as an argument
to the outline() function, so arrow objects now immutable. This should
make the data-flow a little easier to follow.

Accurate shaft length for positive deflection arrows.

Incorrect calculation previously meant that captions for these arrows
were never truncated.

Author: Alistair Jones <alistair.jones@gmail.com>
Revert "Revert "Move pretty printing of ast nodes to ASTNodes""

This reverts commit 853c20d7332cf5d46a7752ceb04352defb9e543a.
Make Pretty take an inner doc gen for rendering child nodes

o Makes ASTNode render using default
o Factors out ToString concern more clearly
Moving ast doc pretty printing to doc builders again but this time using the converter pattern
Pretty-printing collections
Fix astDocBuilder to properly pretty print nested values
Add astStructureDocBuilder for printing both ast and structure
Various pretty printing tweaks

o Support ast.Parameter
o Disable astStructureDocGen for now
o Add Doc.noBreak
Extract core of perty function composition into separate bling package

o Improves error handling
  o Uses total functions to Option to be more aware of error situations
  o Inline with concrete docGens instead of weird outer wrapper
    (error handling is a docGen local concern with a sane default)
o Replaces all of docbuilders and docgenerator types with new DocGen[-T]
o Temporarily disables ast support
o Rename HasDocFormatter => DocFormatting
o Rename HasDocGen => DocHandler
o Rename ASTTerm => ASTPhrase
o Prepares ast printing to use converter pattern (not hooked in / commented out)
Ported tests to use new perty
Fixed minor race in ArrayQueueOutOfOrderSequence
Highlight node on hover using CSS.
Highlight relationship on hover using CSS.
Make relationship caption changeable.

Get relationship caption from template.
Add relationship properties list to inspector.
Hard code '{type}' to default relationship caption.
Merge pull request #2994 from lutovich/fix-minor-race

Fixed minor race in ArrayQueueOutOfOrderSequence
Reverse highligt colors and reuse existing yellow.
Showing first config:maxRows of resultset in table.
Fix: when using page cache in store migration or tools make sure the sweeping thread is running

Registers created standalone page caches in a supplied LifeSupport so that they can be stopped later
Restore node and relationship counts to graph view.

Also restore runTime to table status message.
Style play-topics the same way as help-topcis