Warn about rapidly switching between n programs

[sgrove]

Likely GD needs to have configurable warnings for dev and prod, which is a separate issue, but this is a big one for performance.

If in drawing one frame we gl.useProgram X, gl.useProgram Y, and then at any later point in drawing that frame call gl.useProgram X again, GD should issue a (one time per program run?) warning that it's more efficient to batch all draw calls by program, and highlight that we've useProgram'd X (likely a case for a :name or :id key on programs for debugging) at least twice in one frame. Help newbs (like yours truly) avoid making obvious perf mistakes, especially ones that they may not be aware of.

[kovasb]

I'd prefer to have a separate "logging" driver, and then forms of analysis over that log, rather than put this kind of logic into the basic driver.