This essentially moves the Bengali script from the `Indic' hinter to
the `Latin' hinter.
* src/autofit/afblue.dat: Add blue zone data for Bengali.
* src/autofit/afblue.c, src/autofit/afblue.h: Regenerated.
* src/autofit/afscript.h: Add Bengali standard characters and move
data out of AF_CONFIG_OPTION_INDIC block.
* src/autofit/afranges.c: Move Bengali data out of
AF_CONFIG_OPTION_INDIC block.
* src/autofit/afstyles.h: Update Bengali data; in particular, use
AF_WRITING_SYSTEM_LATIN.