vlib: add a clipboard module (Windows, macOS, X)

vlib/clipboard/clipboard.v

@@ -0,0 +1,45 @@
+module clipboard
+
+// create a new clipboard
+pub fn new() &Clipboard {
+	return new_clipboard()
+}
+
+// copy some text into the clipboard
+pub fn (cb mut Clipboard) copy(text string) bool {
+	return cb.set_text(text)
+}
+
+// get the text from the clipboard
+pub fn (cb mut Clipboard) paste() string {
+	return cb.get_text()
+}
+
+// clear the clipboard
+pub fn (cb mut Clipboard) clear_all() {
+	cb.clear()
+} 
+
+// destroy the clipboard
+pub fn (cb mut Clipboard) destroy() {
+	cb.free()
+}
+
+// check if we own the clipboard
+pub fn (cb mut Clipboard) check_ownership() bool {
+	return cb.has_ownership()
+}
+
+// check if clipboard can be used
+pub fn (cb &Clipboard) is_available() bool {
+	return cb.check_availability()
+}
+
+// create a new PRIMARY clipboard (only supported on Linux)
+pub fn new_primary() &Clipboard {
+	$if linux {
+		return new_x11_clipboard(.primary)
+	} $else {
+		panic("Primary clipboard is not supported on non-Linux systems.")
+	}
+}