getting rid of old unused tests
no need for an intermediate step in some callbacks in world morph
adding capability to remove all event listeners from the Canvas...

…useful because during test playing you don’t want the user  to
interfere
moving the functions to get the tests list and running the system tests in the SystemTestRecorderAndPlayer class
simplifying the filename of the .js for each test, and consequently the test name in the metadata
minor: adding a missing property to the SystemTestsRecorderAndPlayer class
replacing two flags in SystemTestsRecorderAndPlayer  with a slightly more proper state machine of sorts
playing a test now disables user-controlled events
adding a legit way to issue a "delete all morphs" command, with dedicated SystemTestsEvent and all
minor cosmetic change
adjusting the panel - no need for a local method indirection in the callbacks + adding link to delete all morphs
the image saving contained an error that prevented the image from being loaded, fixing
the "test-tools" page now only has two links, and the windows are normal windows rather that minimal panels - cause it's much much easier for opening debugging panels and there was no clear advantage
adding a sample test
renaming "test-tools.html" into "links-to-common-setups.html" as it's perhaps more explanatory
removing a couple of "debugger" statements