Revert "Re-add the #random_string(len) method to pass specs."

This reverts commit bd8918e4e1d7b8cbdb3b923b7e513621e2931910.
Revert "Use actual vars so that jsobfu can randomize."

This reverts commit b9284c56356cbdb62344fc1f75ce8da88b7d0925.
Revert "Use tiny var names by default."

This reverts commit 52432ef482dbdb2e7fb1d52d9da7307b0b329d14.
Revert "Use implicit return for assignment."

This reverts commit 49139cc07fd55c302a49a0d1c202f294bda7eeb2.
Revert "Fixes large-string expansion in JSObfu."

This reverts commit 14fed8c61032661f1f8bc7d83532bcee59d26388.
Land #3247 - Revert #3224 jsobfu string size fixes