Gio::Application: Add add_main_option_entry() and enum OptionType

* gio/src/application.[hg|ccg]: Add add_main_option_entry() and
enum Application::OptionType. Bug #727822.
Gio::Application: Add add_main_option_entry() taking a slot parameter

* gio/src/application.[hg|ccg]: Add add_main_option_entry() and
add_main_option_entry_filename() taking slot parameters.
Add add_main_option_entry_private(). Bug #727822.
Gio::Application: Fix some typos
Gio::Application: Add some @newin{2,42}
Add Gio:SocketSource, SignalSocket and Socket::create_source()

* .gitignore: Add !gio/giomm/socketsource.[cc|h].
* gio/giomm.h:
* gio/giomm/filelist.am: Add socketsource.h.
* gio/giomm/socketsource.[cc|h]: New files. SocketSource and SignalSocket.
* gio/src/socket.[ccg|hg]: Add create_source().
Remove many trailing blanks in socket.hg.
* glib/glibmm/main.[cc|h]: Add functions required when a class derived from
Source is defined in another file. Bug #725281.
examples/network: Use SocketSource and SignalSocket.

* examples/network/socket-client.cc: Use Gio::Socket::create_source().
* examples/network/socket-server.cc: Use Gio::signal_socket().connect().
Bug #725281.
Merge branch 'master' of git://git.gnome.org/glibmm

Conflicts (hopefully resolved):
	.gitignore
JOHNE - Add new source files to 'giomm.vcproj'