[base] Significant optimization of `ft_div64by32'

We shift as many bits as we can into the high register, perform
32-bit division with modulo there, then work through the remaining
bits with long division. This optimization is especially noticeable
for smaller dividends that barely use the high register.

* src/base/ftcalc.c (ft_div64by32): Updated.
[base] Introduce and use new macro `FT_UPDATE_BBOX'

* src/base/ftbbox.c (FT_UPDATE_BBOX): New macro.
(FT_Outline_Get_BBox): Use it here.
[base] Fix Savannah bug #43356.

* src/base/ftbbox.c (BBox_Move_To, BBox_Conic_To): Update bbox in case
of implicit `to'.
(BBox_Line_To): New emitter that does not update bbox.
Formatting.
[base] Small bbox correction.

* src/base/ftbbox.c (FT_Outline_Get_BBox): Start from nonsense bbox
instead of initial point that could be `off' in conic outlines.
[sfnt] Fix Savannah bug #43392.

* src/sfnt/ttsbit.c (tt_sbit_decoder_load_metrics): Don't let
vertical metrics uninitialized.
[autofit] Adjust Devenagari character range.

* src/autofit/afranges.c (af_deva_uniranges): Omit characters that
are common to all other Indic scripts.
[build] Better optimization settings for vc2010 solution file.

* builds/windows/vc2010/freetype.sln,
builds/windows/vc2010/freetype.vcxproj: Updated.
[truetype] Limit delta shift range.

The legal range for delta shift is zero through six. Negative values
are illegal according to
  https://developer.apple.com/fonts/TrueType-Reference-Manual/RM04/Chap4.html#delta%20shift

* src/truetype/ttobjs.h (delta_shift, delta_base): Make unsigned.
* src/truetype/ttinterp.h (DO_SDS): Throw an error if delta_shift
  out of range.
  (Ins_DELTAP, Ins_DELTAC): Optimize for legal delta_shift.
A better fix for Savannah bug #43392.
Suggested by Doug Felt <dougfelt@gmail.com>.

* src/sfnt/ttsbit.c (tt_sbit_decoder_load_metrics): Set
`vertAdvance' to zero...

* src/truetype/ttgload.c (TT_Load_Glyph): ... and set here a default
value for `vertAdvance' based on `linearVertAdvance' in case
`vertAdvance' is zero.  Note that the previous computed ad-hoc value
for `linearVertAdvance' was apparently not tested in a real-life
situation.
Typos.
[cff] Add `CFF_CONFIG_OPTION_DARKENING_PARAMETERS' config macro.

* devel/ftoption.h, include/config/ftoption.h
(CFF_CONFIG_OPTION_DARKENING_PARAMETERS): New macro.

* src/cff/cffobjs.c (SET_DARKENING_PARAMETERS,
SET_DARKENING_PARAMETERS_0): New macros.
(cff_driver_init): Use new macros.
Improve documentation of FT_GlyphSlotRec.

Based on a suggestion by Phil Endecott <freetype@chezphil.org>.
[cmake] Add iOS build support.

* builds/cmake/iOS.cmake: New file.  Universal binaries are built
with both 32 and 64 bit arm architectures.

* CMakeLists.txt (IOS_PLATFORM): New variable for running the iOS
toolchain.  Possible values are `OS' to build on iOS, or
`SIMULATOR' to build on APPLE.
Minor.
[autofit] Add blue-zone support for Telugu.

This essentially moves the Telugu script from the `Indic' hinter to
the `Latin' hinter.

Note that this is a first shot and quite certainly needs
refinements.

* src/autofit/afblue.dat: Add blue zone data for Telugu.

* src/autofit/afblue.c, src/autofit/afblue.h: Regenerated.

* src/autofit/afscript.h: Add Telugu standard characters and move
data out of AF_CONFIG_OPTION_INDIC block.

* src/autofit/afranges.c: Move Telugu data out of
AF_CONFIG_OPTION_INDIC block.

* src/autofit/afstyles.h: Update Telugu data; in particular, use
AF_WRITING_SYSTEM_LATIN.
[truetype] Unwrap engine compensation settings.

* src/truetype/ttobjs.c (tt_size_init_bytecode): Updated.
[build] Add property file to vc2010 project.

This simplifies custom build configurations, especially for
automated build environments.

* builds/windows/vc2010/freetype.user.props: New configuration file.

* builds/windows/vc2010/freetype.vcxproj: Include
`freetype.user.props' and use its data fields.

* builds/windows/vc2010/index.html: Updated.
[truetype] Clean up bytecode rounding.

Zero distance does not have to be treated specially if you follow
specifications and check the sign as the very last step of rounding.

* src/truetype/ttinterp.c (Round_None, Round_To_Grid,
Round_Down_To_Grid, Round_Up_To_Grid, Round_To_Double_Grid): Use
macros when available, do not check for non-zero distance.
(Round_To_Half_Grid, Round_Super, Round_Super_45): Ditto, return phase
if sign changed.
[sbit] Minor fixes.

* src/sfnt/ttsbit.c (tt_face_load_sbit) [TT_SBIT_TABLE_TYPE_SBIX]:
Accept overlay format also, but emit warning message in that case.
(tt_sbit_decoder_load_metrics): Add missing newline to error
message.
(tt_sbit_load_sbix_image): Add `rgbl' graphic type (as used on iOS
7.1) to the list of unsupported formats.