TAG : version bump for RC3

Hopefully the final RC
version bump

back to 1.4.x
backend_qt5.py Don't use six.u

This code already does from __future__ import unicode_literal.
Thus '+' will be a unicode string even in python 2 and there is no
need for converting it into a unicode string. Infact this results in
a TypeError because six.u assumes the input string to be ASCII only.
See http://pythonhosted.org/six/#six.u
Merge pull request #3357 from jenshnielsen/qt4_unicode

backend_qt5.py Don't use six.u
Identification of freetype when 'freetype-config --ftversion' fails.
Merge pull request #3363 from pelson/freetype_identification

BUG/BLD : fix freetype version identification 

Identification of freetype when 'freetype-config --ftversion' fails.
Merge pull request #3372 from ericdill/qt4compat

DOC: Fixed the wording of the qt4_compat.py deprecation warning
Merge branch 'v1.4.x'