COPKGManager: add possibility to manage source feeds for packages

Feeds are saved in opkg config file.

NOTE:Existing config file will be overwrite, so must be reconfigured
via gui.
Source names are strictly numbered src 0...10 (maximmal 10 at the moment)

FIXME: input mask in keyboardinput class is too small for some adresses, large
address names are cutted and makes entries useless


Origin commit data
------------------
Commit: aad5db705f
Author: Thilo Graf <dbt@novatux.de>
Date: 2015-02-04 (Wed, 04 Feb 2015)

src/system/locals_intern.h

@@ -1223,6 +1223,7 @@ const char * locale_real_names[] =
 	"menu.hint_next_brief",
 	"menu.hint_numeric_adjust",
 	"menu.hint_opkg",
+	"menu.hint_opkg_feed_address_edit",
 	"menu.hint_opkg_install_local_package",
 	"menu.hint_opkg_upgrade",
 	"menu.hint_osd",
@@ -1889,9 +1890,12 @@ const char * locale_real_names[] =
 	"opkg.button.info",
 	"opkg.button.install",
 	"opkg.button.uninstall",
+	"opkg.enter.feed.address",
+	"opkg.enter.feed.address.example",
 	"opkg.failure.install",
 	"opkg.failure.update",
 	"opkg.failure.upgrade",
+	"opkg.feed.addresses",
 	"opkg.install.local.package",
 	"opkg.messagebox.reinstall",
 	"opkg.messagebox.remove",