Pause (and settings), Checkpoints, Physics fixes

I've made a few critical changes to the game on account of feedback from my colleagues Justin and Brett, such as fixing malfunctioning trampoline gummy physics. (It's much, much more satisfying now.) I've also added pausing (with escape), and respawning at checkpoints.

It's been a very big week, as seven days ago this was just an idea; but I don't mean to get ahead of myself. In truth this is the culmination of a year of learning not only Godot (I mean, really, really learning Godot) but a number of tricks in Blender, Krita, Audacity, LMMS & Ardour, and a whole assortment of digital media software. The true challenge with this is that I am taking it on solo, if only to prove that any idea, given enough devotion and fervor, can be made real! I couldn't thank the people working at KDE, the Blender Foundation, and a number of other open source projects enough. The community support I've been receiving has really helped me out, too.

My goal of having a downloadable demo for Windows and Linux by Halloween remains active. I will see you then!