Update CFF2 parser to current FreeType branch from Adobe

Probably this will be the last version of FontView that is built from
a separate FreeType branch.  As soon as lemzwerg@ has merged Adobe’s
work in to the master branch of FreeType, we can build FontView from
the FreeType master.

v0.1.6 with better conformance to OpenType 1.8 spec for CFF2

Release FontView v0.1.3

Version 0.1.2

* Users can now manually change the sample text used for rendering.
  Showing a modal dialog box is a terribly clumsy user interface,
  but a good GUI with direct manipulation (like a real text editor)
  would have been much more work to implement.

* If an OpenType font supports multiple language systems, FontView now
  shows a choice menu with the supported languages; selecting a
  language affects text rendering. The font’s default language is
  exposed as “Other language”.

* FontView now supports `*.pfa` files, thanks to @khaledhosny.

* Minor bug fixes.
* Nastaliq fonts are now rendered correctly.

Add screenshot to README