Allow Type 3 subsetting and embedding of TrueType fonts without Postscript glyph name table.

Due do unreliable PostScript glyph name tables in TT fonts, we were previously using the 'uniXXXX' glyph name convention to replace the font provided names. This was limited to font providing the 'post' table tho. This behavior is now extended to TT font without glyph name table, hence allowing Type 3 subsetting and embedding of those fonts (vs only outlining previously).

git-svn-id: file:///svn/Scribus/trunk/Scribus@19396 11d20701-8431-0410-a711-e3c959e3b870