Reset text origin on \fay changes for VSFilter compatibility

Comparing this rendering of this line:

{\fnTahoma\c&H000000&\fs100\an7\fay0.115\pos(240,250)}——————–>{\fay0.0}——>

To this line:

{\fnTahoma\c&H000000&\fs100\an7\fay0.0\pos(240,250)}——————–>{\fay0.0}——>

The second arrow is in the same place for both lines when using
VSFilter, but the origin of the second shear is different when using
libass.

After every change in \fay or a newline, the vertical offset resets
to 0.

Fixes issue #80. Bug report and patch by BwackNinja (BwackNi...@gmail.com)
(this commit corresponds to the patch issue_80_3.patch)
Add ass_library_version()

Based on the patch by chadr123.

See google code issue #113.
Try to make really weird looking macro mess more understandable

The "if (0) {  // cool ;)" is just mindblowing.
Added ass_font_index_magic to fix char indexes in weird encodings
Merge pull request #6 from 11rcombs/ms-symbol-fix

Hack to fix MS Symbol-encoded fonts
Fix compilation with VC++ 2013

For whatever reason FT_Vector points[4] = { ... }; needs to come at the
beginning of a scope. Since that block was duplicated, just extract it
to a function.

This does not include buildsystem support, so actually compiling with
VC++ requires creating a project and supplying a config.h file.

Signed-off-by: wm4 <wm4@nowhere>
Improve blur quality: use volume 65536 and initialize left column
Speed up \blur table generation

Based on xy-VSFilter commit 54391d3a.
Fix mismatched/out-of-bounds accesses in vertical \blur
Don't forget to apply \be to the last row/column
Merge pull request #10 from astiob/blur

Blur fixes
shaper: actually correctly handle @font advance

The code was confusing glyph index and Unicode codepoint.
256df617 attempted a fix but merely moved the wrong code.

Fixes Google Code issue #94.

Vertical ligatures are possibly still broken, but
horizontal ligatures and non-ligatures are correct now.
Parse Angle overrides as floating-point numbers

This complements 5903771e.
Support fractional \org arguments
Stop misparsing and add support for \fsc
Stop animating \b and \i

Unlike what the cc635086 message says, VSFilter does not animate them.
Fix \fs+ and \fs-

The argument is a relative amount. The unit is: \fs+1 = +10%.
A whole bunch of parsing and default value fixes

Obtained by reading the xy-VSFilter source code.
Accept colors with arbitrary sequences of leading & and H
Scale distance to screen plane like blur radius

VSFilter forgets to scale this distance,
just like it forgets to scale blur radius.