Removed stage-based gameplay and end-of-stage enemy waves, made enemy health dependent on wave number, homingenemy speed dependent on wave number
Merge branch 'master' of https://github.com/rikproDVC/Gradius

Conflicts:
	Assets/Resources/Enemies/Scripts/RegularEnemy.cs
	Gradius-csharp.sln
	Gradius.sln
	Gradius.userprefs
Added difficulty system
I SAID!!! Added difficulty system!
Improved variable names, squashed some bugs created by the menu system combined with difficulty system