entity encoding fails with angle follow text

[tbonfort]

GD text rendering by default supports entity encoded text (eg: { é ...)

there's a problem with how these strings are split up glyph by glyph for angle follow text, as for text containing these encodings, msGetLabelSize returns the size of gd rendered glyphs (i.e. é counts for one glyph) whereas the string is split into individual chars when computing the label points.

there's potential for segfaults here as in that case we're fetching label point values outside of what was returned by gd (mapserv segfaults for me, but not shp2img)

example with angle follow vs. angle auto: