Simplify Fancy Filtering

[StartAutomating]

PSSVG should simplify the use of the fancy (and arcane) filtering system in SVG.

It has already done some of this, for example, making drop shadows a little easier to use

• [ ] #43
• [ ] #48

It should do more:

• [ ] #222
• [ ] #223
• [ ] #224
• [ ] #225
• [ ] #226
• [ ] #227
• [ ] #230
• [ ] #231
• [ ] #233