Some libraries that depend on devdraw don't know about 32x32 cursor -- mainly 9fans.net/go/draw.

It is possible to receive multiple screen resize events, and resizeimg would be called for different sizes, before _flushmemscreen actually gets called with rectangle sizes different from the most recent resizeimg call. The size mismatch would trigger illegal memory access inside _flushmemscreen. This commit protects _flushmemscreen by returning early if the requested rectangle is outside of the current texture rectangle.

Fixes bug where devdraw does not "notice" mouse position after task switch. Fixes https://github.com/9fans/plan9port/issues/232.

Fixes #235.

Auto-indent mode leaves trailing spaces on blank lines as you type past them, so silently elide them from the window content as it gets written back to disk. Another option would be to remove them from the window entirely during Put, but they're actually nice to have while editing, and to date Put has never modified the window content.

FreeBSD 11.2 by default does not have gcc.

Use the widely accepted /dev/stdout.