adding sonic-pi-send-line

[derekxkwan]

Not sure if this helpful for others, but found it a bit of work to execute one-liners like require "~/stuff" and function calling. So I basically copied sonic-pi-send-region to make sonic-pi-send-line changing (region-beginning) to (line-beginning-position) and (region-end) to (line-end-position) and bound this to C-c C-w (taking inspiration from C-w/M-w line yanking/copying).

Not 100% on the C-c C-w keybinding but it doesn't seem to clash with any other modes I've got going on in sonic-pi buffers.

[derekxkwan]

Or maybe this sort of functionality could get merged into sonic-pi-send-region if no region is selected in the interest of not polluting keybinding space?