Starfield now generates stars at startup rather than load them from the
server - approx. 50msec to load 50,000 stars.
STAR_COLORIZATION const in Generator.cpp is used to defined how
colorful the stars should be.
STARFIELD_NUM_STARS and STARFIELD_SEED sets the number of stars and the
random number seed used to generate the starfield.
o allows UrlReader to cache the downloaded content in a local (updating it
automatically when the server indicates a newer time stamp)
o retires the FieldOfView class
o makes the stars move again
o fixes bad deletion in UrlReader (delete instead of delete[])
o allows UrlReader to advertise supported compression algorithms to the server
