Cleanup OpenSymbol vertical metrics

OS/2 sTypoDescender should be -ve not positive, and the hhea and OS/2
values should agree. Also OS/2 usWinAscent/Descent should be big enough
for any glyph in the font.

Change-Id: Iad201f268f4e030565795e858a5a42937328ec80
Reviewed-on: https://gerrit.libreoffice.org/31060Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Khaled Hosny <khaledhosny@eglug.org>

extras/source/truetype/symbol/OpenSymbol.sfd

@@ -4,7 +4,7 @@ FullName: OpenSymbol
 FamilyName: OpenSymbol
 Weight: Book
 Copyright: (c) 2009 Sun Microsystems Inc.\nTHERE DOES NOT EXIST (c) 2011 Julien Nabet\nPRECEDES <-> DOES NOT SUCCEED (c) 2011 Olivier Hallot\nPRIME <-> TRIPLE PRIME (c) 2013 Mathias Hasselmann\nphi <-> phi1 (c) 2015 Khaled Hosny\n(c) 2016 Mike Kaganski\nzero, one, two, three, four, five, six, seven, eight, nine, question, underscore, copyright, registered, uni2215, angle, therefore, lozenge (c) 2010 Google Corporation
-Version: 102.9
+Version: 102.10
 ItalicAngle: 0
 UnderlinePosition: -143
 UnderlineWidth: 20
@@ -20,26 +20,26 @@ OS2Version: 0
 OS2_WeightWidthSlopeOnly: 0
 OS2_UseTypoMetrics: 1
 CreationTime: 1144938807
-ModificationTime: 1479471125
+ModificationTime: 1479754802
 PfmFamily: 81
 TTFWeight: 400
 TTFWidth: 5
-LineGap: 0
+LineGap: 307
 VLineGap: 0
 Panose: 5 1 0 0 0 0 0 0 0 0
-OS2TypoAscent: 0
-OS2TypoAOffset: 1
-OS2TypoDescent: 820
-OS2TypoDOffset: 1
-OS2TypoLinegap: 0
-OS2WinAscent: -240
+OS2TypoAscent: 1420
+OS2TypoAOffset: 0
+OS2TypoDescent: -442
+OS2TypoDOffset: 0
+OS2TypoLinegap: 307
+OS2WinAscent: 0
 OS2WinAOffset: 1
-OS2WinDescent: -231
+OS2WinDescent: 0
 OS2WinDOffset: 1
-HheadAscent: 0
-HheadAOffset: 1
-HheadDescent: 0
-HheadDOffset: 1
+HheadAscent: 1420
+HheadAOffset: 0
+HheadDescent: -442
+HheadDOffset: 0
 OS2SubXSize: 409
 OS2SubYSize: 409
 OS2SubXOff: 0