Amy spark authored Jul 20, 2020 and Dmitry Kazakov committed Jul 22, 2020

This commit adds automatic detection of compiler triplet and
architecture. This allows to dynamically choose the system library path,
copy them, and then rename the AppImage according to the underlying
platform (instead of hardcoding x86_64).

Additionally, this commit:
* skips Vc (a known broken dependency) on these platforms
* fixes libheif to skip 10-bit and 12-bit decoding (which is broken too
  as of 3.4, see https://bitbucket.org/multicoreware/x265/issues/549)