Add #ifndef/#endif blocks to adjustable defines

This change allows several key build-time parameters, including
ADVANCE, NSAMP, NTRIAL, PATIENCE, RUNTM, STOPRT and STOPTM to be set on
the compiler command line.

The default PATIENCE value is increased to 10, to reflect the fact that
modern computers have frequent interruptions and increase accuracy of
benchmark results.
Add Makefile and fix typo in defines
Add parameter support in Makefile

Parameters such as ADVANCE and PATIENCE can now be specified in the
Makefile, dramatically easing configuration and compilation of the
program.

I have yet to update the documentation; that will be done next.
Use common variable for parameters in Makefile

By storing the whole string of parameters into one variable inside the
Makefile, maintenance of the Makefile is eased and users can insert
arbitrary custom parameters to the compiler.
Update README
Prepare for 0.2.0 release