Fix #12: Implement workaround for application < foo.txt

This patch implements a workaround for issue #12, i.e. when an I/O
watcher for redirected stdin is registered and causes epoll_ctl()
to return EPERM.

The workaround registers the watcher as `active = -1` and bypasses
the epoll_wait() call in the main loop until all data has been read
from stdin and the temporary -1 watcher(s) have completed.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

src/private.h

@@ -46,6 +46,7 @@ typedef struct {
 	int             fd;     /* For epoll() */
 	uint32_t        errors;
 	LIST_HEAD(,uev) watchers;
+	uint32_t        workaround; /* For workarounds, e.g. redirected stdin */
 } uev_ctx_t;
 
 /* Forward declare due to dependencys, don't try this at home kids. */