Improve SahiScriptError Timeout time

since #219 is done, check if we can reduce the timeout of 150s:

Sahi code in lib.js row: 145 this.maxCycles = ScriptRunner.getMaxCyclesForPageLoad() + 300;

Properties to check:

   script.time_between_steps=100
   script.max_cycles_for_page_load=1200
   (100ms*1200=120s + 30s = 150s   -->   30s fixed time out)

Due to the fact, that the max_cycles_for_page_load also affects the maximal waiting timeout for ajax requests, we have to test the impact if we change this properties