smart_split should be more versatile

[Paul O’Shannessy]

smart_split should accept input such that the following is true:

>>> list(smart_split(r"A variable='value' should work."))
[u'A', u"variable='value'" u'should' u'work']
>>> list(smart_split(r"A variable='value with spaces' should also work."))
[u'A', u"variable='value with spaces'", u'should', u'also', u'work.']

With this, multiple word strings can be passed to variables in a template.

[Paul O’Shannessy]

Patch v0.1

[dc]

Duplicate of #6271