Log Message:
Update to 0.9.12:

Overview of changes leading to 0.9.12
Thursday, January 18, 2013
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- Build fixes for Sun compiler.
- Minor bug fix.

Overview of changes leading to 0.9.11
Thursday, January 10, 2013
=====================================

- Build fixes.
- Fix GPOS mark attachment with null Anchor offsets.
- [Indic] Fix old-spec reordering of viramas if sequence ends in one.
- Fix multi-threaded shaper data creation crash.
- Add atomic ops for Solaris.

API changes:
- Rename hb_buffer_clear() to hb_buffer_clear_contents().