Fix log_event and add save_log_file.
Add a lot of simulation logic

Still testing the sim logic, not complete yet.
Add more sim logic.

Simulation appears to be complete, but that is not for sure yet.
Add more sim logic. Definitely not complete yet.

Forgot to add the different loading times to the different plane types.
Now it runs, but the taxi is misbehaving.  When finishing deberthing a plane,
it checks to see if the runway is empty, or if the berths are full, and if
so, it just goes back to the berths and is idle again.  But the problem is,
there will be a couple hundred planes in the runway queue and it will still
decide to just mosey on back to the berths and wait.  The jerk.

Definitely need to fix.
Taxi now behaves correctly.
Storm bug fixed.
Add input file, and add global struct G to handle input values.

Program so far reads input file and loads values into G.  Format of input
file is simply <string> <string> <value>.  It doesn't matter what the strings
are, just the order of the values.

Program does not use G for values yet, it still uses the #define constants in
the header.
Replace #define constants with loaded input values. Not tested.
Change units of G to minutes instead of hours.
Fix time unit conversion bug.

In the berth and deberth methods, when the method was scheduling the
finish time, it was using the incorrect time units to schedule the new
time.
Add TODO to readme.
Make finished berths deberth by time priority.

The way the simulation checked for a finished berth was that it looped
through the berths array and returned the first finished one.  Now it
returns the berth that finished earliest, no matter what.
Merge pull request #8 from daniel-ault/master

Current code