Draw2D touch version 4.5.0 released

+ add new locator for connection labels. ParallelMidpointLocator and change the example "connection_locator" to demonstrate this feature. quite cool.
+ enhance the "connection_locator" example to demonstrate how to use a context menu during connection creation.
+ fixing blury lines. remove unwanted outline SVG element if the outlineStroke=0 or outlineColor=null
+ minor bug and performance fixes in line and connection handling.
+ fixing wrong port assignment in the DBFigure.js in the example "shape_db". Now the document can read/write correct via JSON.