site: output buffering & flushing

[carloscortonc]

Instead of sending output directly to renderer:

cli-er/site/src/main.js

Lines 30 to 32 in 9e9a2c1

	const r = (...args) => renderer.renderOutput(...args);
	process.stdout.write = (v) => r(v);
	process.stderr.write = (v) => r(v, { error: true });

• Send to corresponding "file-descriptors" (stdout=1, stderr=2), using convention /proc/xx/fd/{fd}
• When output need to be rendered: flush it. Read the corresponding fd file, render it, and empty it
• When output needs to be captured (inside quotes, pipe operator, etc): flush it without rendering it, and use the flushed value