rewrote set component of preset_node to allow for empty [set< message, adjusted and expanded documentation

reworked how default hub and node now are given context via null global symbol s_ to make things more streamlined.

added "set" option to the preset_node to allow dynamic switching between hubs. added ability to have argument-less hubs and nodes that automatically default to "default." minor clean-ups...

fixed a sneaky bug where in specific cases preset was assigned to the wrong node, resulting in potential crashes

disabled drawing of tooltip arrows and improved positioning of floating tooltips due to unreliable nature of tcl.

This reverts commit f0435389.