Out of memory in IE11

[Kagami]

IE11 doesn't like the current memory defaults (128M for decoder, 256M for encoder) and fails when trying to encode more than 1 second of sample (0.1 second works fine). VM has 8G of memory.

Currently I set TOTAL_MEMORY to 64M for IE <= 11, but it may be worth to search for better defaults/solution. Unfortunately we can't make this fully customizable because file prober runs at the startup and IE11 still fails on 128M decoder + 64M encoder.