Incompatible Type Error in InstanceMap

[mishaturnbull]

An error has been introduced in pull #8 that manifests in net.sf.openrocket.rocketcomponent.InstanceMap line 34:

Error:(34, 34) java: incompatible types: java.util.ArrayList<java.lang.Object> cannot be converted to java.util.ArrayList<net.sf.openrocket.rocketcomponent.InstanceContext>

Changing the line from

put(key, new ArrayList<>());

to

put(key, new ArrayList<InstanceContext>());

fixes this particular error, but then there are more issues that pop up in other files relating to a .getClass() method.

[mishaturnbull]

Note: this bug does not exist on teyrana/openrocket:alpha12. Opening a PR from that branch into UND-ARC/openrocket:unstable displays one commit different, being commit number bb333ee. Not sure why this commit makes any difference.