Fix the build with Qt 5.6.{2,3}

Building PyQt 5.7 with versions of Qt older than Qt 5.7 is supposed to
work, but currently fails in practice. In fact, this is due to the
fact that the %Timeline variable in QtCoremod.sip didn't contain the
5.6.{2,3} Qt versions, so if this version was used, PyQt was assuming it
was the later version 5.7, and therefore started enabling APIs only
available in Qt 5.7, causing build failures when building against Qt
5.6.{2,3}.

Adding Qt_5_6_2 and Qt_5_6_3 to the timeline fixes this problem. This
fix was suggested by Phil Thompson <phil@riverbankcomputing.com>.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

Index: PyQt5_gpl-5.7/sip/QtCore/QtCoremod.sip
===================================================================
--- PyQt5_gpl-5.7.orig/sip/QtCore/QtCoremod.sip	2016-07-25 15:55:37.000000000 +0200
+++ PyQt5_gpl-5.7/sip/QtCore/QtCoremod.sip	2016-10-26 15:45:43.577153825 +0200
@@ -22,7 +22,7 @@
 
 %Module(name=PyQt5.QtCore, call_super_init=True, default_VirtualErrorHandler=PyQt5, keyword_arguments="Optional", version=1)
 
-%Timeline {Qt_5_0_0 Qt_5_0_1 Qt_5_0_2 Qt_5_1_0 Qt_5_1_1 Qt_5_2_0 Qt_5_2_1 Qt_5_3_0 Qt_5_3_1 Qt_5_3_2 Qt_5_4_0 Qt_5_4_1 Qt_5_4_2 Qt_5_5_0 Qt_5_5_1 Qt_5_6_0 Qt_5_6_1 Qt_5_7_0}
+%Timeline {Qt_5_0_0 Qt_5_0_1 Qt_5_0_2 Qt_5_1_0 Qt_5_1_1 Qt_5_2_0 Qt_5_2_1 Qt_5_3_0 Qt_5_3_1 Qt_5_3_2 Qt_5_4_0 Qt_5_4_1 Qt_5_4_2 Qt_5_5_0 Qt_5_5_1 Qt_5_6_0 Qt_5_6_1 Qt_5_6_2 Qt_5_6_3 Qt_5_7_0}
 
 %Platforms {WS_X11 WS_WIN WS_MACX}