Stefanescu-Jirsa 3D model requires way too much RAM

1. A simulation was set up with default values and:

Model: Stefanescu-Jirsa 3D
Simulation length: 3000 ms
Monitor: BOLD/BOLD ROI

BOLD: Same error as in TVB-1946
BOLD ROI: Error: 37 GB of RAM required, only 27 GB available.

However, in TVB 1.3 this simulation setting (with BOLD) runs without problems. (BOLD ROI untested here.)

2. Same simulation with 2D Oscillator runs unusally long in 1.4.1. But it is suspicious that 2D Oscillator in 1.4.1 takes more than Stefanescu-Jirsa in 1.3 so we assume a (related?) problem here as well.