2020-06-19  Anuj Verma  <anujv@iitbhilai.ac.in>

	* include/freetype/ftimage.h (FT_Render_Mode_): Added new
	  pixel mode `FT_PIXEL_MODE_GRAY16' which will be used
	  to represent signed values while rendering to SDF bitmap.

2020-06-19  Anuj Verma  <anujv@iitbhilai.ac.in>

	* include/freetype/freetype.h (FT_Render_Mode_): Added new
	  rendermode `FT_RENDER_MODE_SDF' which will be used by the
	  `sdf' module to generate signed distance fields from glyph's
	  outline.

	* src/sdf/ftsdfrend.h, src/sdf/module.mk, src/sdf/rules.mk:
	  Add a new line at the end of files.

2020-06-18  Anuj Verma  <anujv@iitbhilai.ac.in>

	[sdf] Added the structure of a new module to render
	signed distance fields.

	* src/sdf/sdf.c, src/sdf/ftsdfrend.c, src/sdf/ftsdf.c,
	  src/sdf/ftsdfrend.h, src/sdf/ftsdf.h, src/sdf/ftsdferrs.h:
	  Added files required by the `sdf' renderer module and added
	  the basic structure and functions required.

	* src/sdf/rules.mk, src/sdf/module.mk: Added files required to
	  build the `sdf' module using the default build system.

	* CMakeLists.txt (`BASE_SRCS'): Add `src/sdf/sdf.c' to the variable.

	* include/freetype/config/ftmodule.h: Added `sdf' module 
	  declaration so that the module can be compiled when not compiling
	  with GNU make.

	* modules.cfg (RASTER_MODULES): Include `sdf' module to the default
	  rasterizer module list.

	* include/freetype/ftmoderr.h: sdf module error define