draft for "mode" XML support

allowed modes:
PROP == (default) proparation of the orbit
SIM ==  simulation of the data from satellite
CALC == calculation of the orbit based on any of the data : PING, GPS,
PULSAR
OPTIM = calculation of the engines firing to reach the moon
aloowed simulation modes
TLE - data == read TLE and calculate position on the specific time
PING - data == simulate ping messages from ground station to satellite
(at specific time from all ground stations)
GPS  - data == simulate GPS's raw data from GPS satellites at specific
time from GPS satellites
PULSAR - data == simulate PULSAR receving signal from all pulsars at
specific time
TLE and PING output data is the same: for PING:
Time=<time>, TimeErr=<time(d)>, PosX=<X(m)>, PosY=<Y(m)>, PosZ=<Z(m)>,
PosErr=<error(m)> pingD1=<time(d) from GS->sat>, PingD11Err=<time(d)>
PingDel=<time(d) of processing data on sat>, PingDelErr=<time(d)>,
PingD2=<time(d) from Sat to GS>, PingD2Err=<time(d)>
for TLE:
Time=<time-from-simulation-output-time>, TimeErr=0,
PosX=<X(m) position of the sat related to the earth>, PosY=<Y(m)>,
PosZ=<Z(m)>, PosErr=<error(m) of the position>
pingD1=0, PingD11Err=0, PingDel=0, PingDelErr=0, PingD2=0, PingD2Err=0
for GPS:
Time=<time-from-simulation-output-time>, GPS=<ID>, UTC=<time UTC from
SAT>,
RawX=<X(m)> RawY=<Y(m)> RawZ=<Z(m)> RawVX=<VX(m)> RawVY=<VY(m)>
RawVZ=<VZ(m)>
for PULSAR:
Time=<time-from-simulation-output-time>, PULSAR=<ID>, DaltaT=<time btw
two pulsars signals>