hypseus-singe v2.8.3

This release changelog:

• -vertical_stretch reimplemented for cliff overlay. See #78 ^*
• -blank_blue enables YUV#1DEB6B (blue) blanking screens.^**
• -manymouse is now a global argument (only Singe will currently enable).
• Singe 'cursor drift' bug fixed when using latest game LUA

Misc news:

• A Discord server has been created.
• Windows binaries linked with -subsystem,windows are available. See #81

^{* -vertical_stretch 24 completely removes letterbox overlay in cliff.
** YUV signal loss blanking: demo and here}