Added various compilation options.

Three build types are now specified: the ‘dev’ build, invoked as “make
dev”, produces a build with maximum debugging info produced and all
warnings turned on (except sometimes-uninitialized, which is annoying
to say the least…); the ‘prof’ build, invoked as “make prof”, produces
a build tailored to profiling the optimized code using gprof; and the
‘actual’ build, invoked as “make actual” produces a build designed for
final use by the end user.
Minor changes, some debugging prints added.
Debugging calls added, some other minor changes.
Minor changes.
Code simplified, two methods for calculating distance were combined to one generalized form.
Old bool.h file deleted.
New boolean.h file added to not conflict with stdbool
Minor changes.
Particle system structure and build methods added.