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.

Defaults.HC

@@ -0,0 +1,11 @@
+/* default configuration */
+
+saphir.border.focus_bg = saphir.border.bg = BLACK;
+saphir.border.focus_fg = LTRED;
+saphir.border.fg = LTGRAY;
+
+saphir.cursor.bg = CYAN;
+saphir.cursor.fg = WHITE;
+
+saphir.blink = TRUE;
+// saphir.border.list = TRUE;