Hiding of dice variants, "jump to" navigation, and updating of UI while
calculating for progress information

Version bump to v0.3.0

UI needs work in different areas:
	- group hiding/collapsing of variants [straightforward]
	- asyncify [might be fine, might blow everything up]

Uses default Asphodice class, rolls sets of 1..10 dice 100000 times for
stats.

Future work will need minor extensions of base Asphodice class, such as:
	- class short name (for HTML element ids)
	- class description (to explain what mechanics are implemented-
	  eg different successCutoff)

FE will also need adapted:
	- ids will need to use class short names (as above)
		- result cards
		- chart canvases
		- tables
	- anchors for 'jump to' navigation (see next item)
	- grouping of dice class results with show/hide groups (or
	  tabs or some other means of selecting results, eg dropdown), eg:
		- Asphodice
			- d=1
			- d=2
			- ...
			- d=10
		- AsphodiceCutoff8
			- d=1
			- d=2
			- ...
			- d=10
		- AsphodiceCrits
			- d=1
			- d=2
			- ...
			- d=10
		 (etc)

In dev mode this means changes to ts files can now be watched
live.

Can now build all with 'gulp' (if gulp-cli installed)

Big commit. Breakdown:
 - .gitignore includes gulpfile.js (otehrwise excluded)
 - gulpfile sets up build steps + browsersync
 - src/ files for FE (stub for now)
 - moved ts to src/ for consistency
 - update tsconfig with new paths
 - package.json lists new reqs