gen-egg-recipes: usage prints to stdout/stderr according to exit-code

Signed-off-by: Mario Domenech Goulart <mario@ossystems.com.br>
gen-egg-recipes: automatically add patches to SRC_URI

gen-egg-recipes will search for patches on directories
chicken-egg-<egg>-<version> in the egg recipes dir.

Signed-off-by: Mario Domenech Goulart <mario@ossystems.com.br>
chicken-egg-dbus: add patch for error handling

Signed-off-by: Mario Domenech Goulart <mario@ossystems.com.br>
chicken-egg-dbus: remove patch specific to version 0.91 (whose recipe has been removed)

Signed-off-by: Mario Domenech Goulart <mario@ossystems.com.br>