force_style not recognizing more than one filter.

[chaz8900]

Summary of the bug: When trying to format subtitles (.srt for example) only the first style change is recognized.
How to reproduce: Utilize force_style on a subtitle file with more than one style changes.

% ffmpeg -f lavfi -i  color=c=red:s=640x480:d=40 -vf subtitles=/Users/user/Documents/srtTest/test37.srt:force_style='Alignment=10,Outline=0' out.mp4
ffmpeg version 3.0.2 Copyright (c) 2000-2016 the FFmpeg developers
  built with Apple LLVM version 7.3.0 (clang-703.0.31)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/3.0.2 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-opencl --enable-libx264 --enable-libmp3lame --enable-libxvid --enable-libfreetype --enable-libvorbis --enable-libvpx --enable-libass --enable-ffplay --enable-libfdk-aac --enable-libopus --enable-libx265 --enable-nonfree --enable-vda
  libavutil      55. 17.103 / 55. 17.103
  libavcodec     57. 24.102 / 57. 24.102
  libavformat    57. 25.100 / 57. 25.100
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 31.100 /  6. 31.100
  libavresample   3.  0.  0 /  3.  0.  0
  libswscale      4.  0.100 /  4.  0.100
  libswresample   2.  0.101 /  2.  0.101
  libpostproc    54.  0.100 / 54.  0.100
Input #0, lavfi, from 'color=c=red:s=640x480:d=40':
  Duration: N/A, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 640x480 [SAR 1:1 DAR 4:3], 25 tbr, 25 tbn, 25 tbc
File 'out.mp4' already exists. Overwrite ? [y/N] y
[Parsed_subtitles_0 @ 0x7fd9fb416de0] Shaper: FriBidi 0.19.7 (SIMPLE) HarfBuzz-ng 1.2.6 (COMPLEX)
[Parsed_subtitles_0 @ 0x7fd9fb416de0] Using font provider coretext
[AVFilterGraph @ 0x7fd9fb600300] No such filter: 'Outline'
Error opening filters!

[llogan]

Enclose your filtergraph in double quotes or escape the single quotes.
https://ffmpeg.org/ffmpeg-utils.html#Quoting-and-escaping