Fix warnings on non-static data member initializers (C++11 feature)

We're not formally using C++11 yet so those trigger compilation warnings
(at least with GCC 5):

./main/input_default.h:122:30: warning: non-static data member initializers only available with -std=c++11 or -std=gnu++11
  CursorShape default_shape = CURSOR_ARROW;
                              ^

Note: We may allow those eventually (especially for non-int static const),
but most of current occurrences were inconsistent with all other classes.

See also http://www.stroustrup.com/C++11FAQ.html#member-init

visual_script_editor.cpp

@@ -3496,6 +3496,7 @@ VisualScriptEditor::VisualScriptEditor() {
 		clipboard = memnew(Clipboard);
 	}
 	updating_graph = false;
+	seq_connect = false;
 
 	edit_menu = memnew(MenuButton);
 	edit_menu->set_text(TTR("Edit"));

visual_script_editor.h

@@ -37,6 +37,7 @@
 #include "scene/gui/graph_edit.h"
 #include "visual_script.h"
 #include "visual_script_property_selector.h"
+
 class VisualScriptEditorSignalEdit;
 class VisualScriptEditorVariableEdit;
 
@@ -159,7 +160,7 @@ class VisualScriptEditor : public ScriptEditorBase {
 	MemberType member_type;
 	String member_name;
 
-	bool seq_connect = false;
+	bool seq_connect;
 
 	PortAction port_action;
 	int port_action_node;

visual_script_property_selector.cpp

@@ -721,6 +721,7 @@ VisualScriptPropertySelector::VisualScriptPropertySelector() {
 	search_options->set_hide_root(true);
 	search_options->set_hide_folding(true);
 	virtuals_only = false;
+	seq_connect = false;
 	help_bit = memnew(EditorHelpBit);
 	vbc->add_margin_child(TTR("Description:"), help_bit);
 	help_bit->connect("request_hide", this, "_closed");

visual_script_property_selector.h

@@ -63,8 +63,7 @@ class VisualScriptPropertySelector : public ConfirmationDialog {
 	ObjectID script;
 	Object *instance;
 	bool virtuals_only;
-
-	bool seq_connect = false;
+	bool seq_connect;
 
 	void _item_selected();