Initial basic functionality commit

What this commit adds:
* Ability to apply a theme, given a folder
* Extract all .zip files in /Themes/ into a relevant folder
* Get all theme metadata from info.smdh
* Proper unicode handling

What's still needed for initial release:
* Theme shuffling
* GUI

source/ui.c

@@ -0,0 +1,50 @@
+#include <3ds.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "ui.h"
+
+Color makeColor(char r, char g, char b)
+{
+	Color n;
+	n.rC = r;
+	n.gC = g;
+	n.bC = b;
+
+	return n;
+}
+
+s8 drawPixel(u32 x, u32 y, Color c, u8* screen)
+{
+	u8 height=240;
+	u32 v=(height-1-y+x*height)*3;
+	screen[v]=c.bC;
+	screen[v+1]=c.gC;
+	screen[v+2]=c.rC;
+
+ return 0;
+}
+
+s8 drawLine(u32 x1, u32 y1, u32 x2, u32 y2, Color c, u8* screen)
+{
+	u32 x, y;
+	if(x1 == x2)
+	{
+		if (y1<y2) for (y = y1; y < y2; y++) drawPixel(x1,y,c,screen);
+			else for (y = y2; y < y1; y++) drawPixel(x1,y,c,screen);
+	}else{
+		if (x1<x2) for (x = x1; x < x2; x++) drawPixel(x,y1,c,screen);
+			else for (x = x2; x < x1; x++) drawPixel(x,y1,c,screen);
+	}
+ return 0;
+}
+
+s8 drawRect(u32 x1, u32 y1, u32 x2, u32 y2, Color c, u8* screen)
+{
+	drawLine( x1, y1, x2, y1, c, screen);
+	drawLine( x2, y1, x2, y2, c, screen);
+	drawLine( x1, y2, x2, y2, c, screen);
+	drawLine( x1, y1, x1, y2, c, screen);
+ return 0;
+}