made AGM_GForces more realistic

made the module hopefully a bit more realistic and used reallife values
source of informations is just wikipedia, but...
also increased AVERAGEDURATION and descreased INTERVAL to make the change more fluid

source: http://en.wikipedia.org/wiki/G-LOC
untrained persons without gsuit will fall unconscious between 4 and 6G
pilots in gsuits will sustain up to 9G
a person is for average 12 seconds unconscious
after being unconscious, a person is unable to do simple tasks for average 15 seconds

in independent jet is now nearly impossible to fall unconscious
but in the opfor jet its pretty easy especially as nonpilot
this and line 90 makes a more fluid feeling of greyout/redout, the old implementation jumps more