Fixed for rendering non breaking spaces (cid:160)

As stated in the PDF specification ISO 32000-1, table in Annex D.2 Latin Character Set and Encodings page 653 to 656 (available here: http://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/PDF32000_2008.pdf):
"The SPACE character shall also be encoded as 312 in MacRomanEncoding and as 240 in WinAnsiEncoding. This duplicate code shall signify a nonbreaking space; it shall be typographically the same as (U+003A) SPACE."
The duplicate key was missing, therefore PDFMiner was returning the string "(cid:160)". 

This fix adds the duplicate key in latin_enc.py
glyphlist.py does not need to be modified as it already contains a key for non breaking space https://github.com/lucanaso/pdfminer/blob/master/pdfminer/glyphlist.py#L2755.

pdfminer/latin_enc.py

@@ -162,6 +162,7 @@ ENCODING = [
   ('mu', None, 181, 181, 181),
   ('multiply', None, None, 215, 215),
   ('n', 110, 110, 110, 110),
+  ('nbspace',  None, 202, 160, None),
   ('nine', 57, 57, 57, 57),
   ('ntilde', None, 150, 241, 241),
   ('numbersign', 35, 35, 35, 35),