_cairo_cache_preserve -> _cairo_cache_freeze _cairo_cache_release -> _cairo_cache_thaw
Track rename of _cairo_cache_freeze/thaw.
Track rename. Add stacking behavior to _cairo_cache_freeze/thaw. Abstract out shrinking from _cairo_cache_insert so that _cairo_cache_thaw will also shrink as necessary.
Make this function static since its current limitation to accept an entry rather than a key makes it not as externally useful as would be desirable. Document this limitation.
Replace cairo cache implementation (this code from cworth)
No more global glyph cache to clean up
Store glyphs in new per-scaled font caches which hold user-space metrics and device space bounding boxes
Refactor glyph drawing APIs so that the surface API is invoked directly from the gstate code.
Add path creation/destruction routines (to hold glyph paths)
New implementation of scaled fonts which uses per-scaled_font caches for glyphs and keeps user-space metrics, device-space bboxes along with glyph images and/or glyph paths.
Adapt to new scaled font API changes.
New cache and scaled_font APIs
Repond to bug fix in metrics computation for glyphs where y values were rounded up instead of down because of a sign difference between cairo and FreeType.
Reviewed by: otaylor, cworth
