• Fixed bug when entering and exiting the debugger; sometimes the character corresponding to the '`' key would be output in the prompt area.
• Updated DPC+ Thumb ARM emulation code to latest from David Welch. In particular, this fixes incorrect handling of the V flag when adding and subtracting, but also fixes compile-time warnings that I couldn't get rid of before.
• Updated UNIX configure script to work with GCC 6.x compilers, and to remove references to obsolete compiler versions that can no longer be used to compile Stella.