feat(c/libuv): Add tcp, udp, poll, core, stream, err features

feat(c/io): add libuv async io with io, tcp, udp, timer, dns, loop

feat(c/io): add libuv async io with stream, req, handle

feat(c/libuv): rename c/io to c/libuv, and improve errro, net, handle, stream

feat(c/libuv): Add a libuv demo: echo_server

refactor(c/libuv): Adjust comments and file names to accommodate merge

c/libuv/timer.go

@@ -0,0 +1,42 @@
+package libuv
+
+import (
+	"github.com/goplus/llgo/c"
+	_ "unsafe"
+)
+
+// llgo:type C
+type TimerCb func(timer *Timer)
+
+/* TimerT related function and method */
+
+//go:linkname InitTimer C.uv_timer_init
+func InitTimer(loop *Loop, timer *Timer) c.Int
+
+// llgo:link (*Timer).Start C.uv_timer_start
+func (timer *Timer) Start(cb TimerCb, timeout uint64, repeat uint64) c.Int {
+	return 0
+}
+
+// llgo:link (*Timer).Stop C.uv_timer_stop
+func (timer *Timer) Stop() c.Int {
+	return 0
+}
+
+// llgo:link (*Timer).Again C.uv_timer_again
+func (timer *Timer) Again() c.Int {
+	return 0
+}
+
+// llgo:link (*Timer).SetRepeat C.uv_timer_set_repeat
+func (timer *Timer) SetRepeat(repeat uint64) {}
+
+// llgo:link (*Timer).GetRepeat C.uv_timer_get_repeat
+func (timer *Timer) GetRepeat() uint64 {
+	return 0
+}
+
+// llgo:link (*Timer).GetDueIn C.uv_timer_get_due_in
+func (timer *Timer) GetDueIn() uint64 {
+	return 0
+}