Refactor everything

We now hijack existing system functions to integrate with `WinMgr`,
instead of `Spawn`ing our own `SaphirTask`.

Also, you can now use `Saphir(Bool)` to toggle enable/disable the
features.

There is a global var `saphir` which values are set by `Defaults.HC` for
colors and other behaviors; these values can be changed at any time.

Saphir/Class.HC

@@ -0,0 +1,30 @@
+class SaphirAttr {
+    I64 fg;
+    I64 bg;
+};
+
+class SaphirBorder : SaphirAttr {
+    I64 focus_fg;
+    I64 focus_bg;
+    Bool list;
+};
+
+class SaphirCursor : SaphirAttr {
+    // Bool blink;
+    U64 stub;
+};
+
+class SaphirKeyDev {
+    U64 sys_cbs;
+    U64 null_cbs;
+}
+
+class SaphirGlbls {
+    Bool enabled;
+    Bool blink;
+    SaphirBorder border;
+    SaphirCursor cursor;
+    SaphirKeyDev kd;
+    I64 doc_cursor_state;
+} saphir;
+MemSet(&saphir, 0, sizeof(SaphirGlbls));