Stopped supported -0 as a float output because (a) it is non-portable, only existing on some architectures and (b) relies on the undefined behavior of 1.0/0.0

- fixed ANSI (C89) issues, including #418

Add TEST_MESSAGE for outputting messages without aborting a test and _MESSAGE variant to TEST_PASS collection.

- Running time macros have been made more portable, previously it was not
  possible to override all macros
- Running time macros will be executed by default test runner, and auto test
  runners
- Adds a default execution time implementation for unix. (Previous default
  implementation only worked on Windows)
- For embedded platforms there is a simple method of getting a default
  implementation by defining a single macro UNITY_CLOCK_MS()
- Removed need for UNITY_EXEC_TIME_RESET. This was not being used for the default
  implementations, if anything ever did need reset-like functionality it could
  simply be wrapped up with the start or stop macros for that platform

The existing implementation was not very good:
 - It printed all very small values as "0.000000..."
 - It did not distinguish positive and negative zero
 - In some cases it printed extra garbage digits for single-precision values
   (e.g. 3.9e+30 was printed as 3.90000013+30)

Tests have been updated to check that we now match printf("%.6g") for
1,000,000 randomly chosen values, except for rounding of the 6th digit.

Correct clean target and print test fails during coverage in Makefile

Using this option changes the control flow of Unity, but is useful on
constrained embedded systems. You can't fully simulate the power of
'longjmp' with just 'return', but Unity still works well, all tests pass.

Originated from commit c6dc96f3 but are rarely used and not in math.h
Removes float to double promotion warning and simplifies the code
'gcc -std=gnu99 -Wdouble-promotion' spits out these warnings

Revised internal type naming scheme to better sandbox Unity away from everything else. Sure, short was nice, but not at the expense of naming collisions.

Takes about 10 minutes to run all floats, so split into 3 tests for parallel
running later. This was useful during development for finding hard corner cases
and getting the routine to high quality. Off by default.
Note that all floats 16.0 and up can be represented uniquely (in this format) and will
round-trip back to the exact same float with sscanf(). This property is true for
UnityPrintFloat, despite a few rounding error cases, it will produce output identity.

Better comments and refactor on round ties to even
Add upper threshold value on round to even feature since numerical precision issues
start to give approximations when dividing one large double by another. When tested
on float values, using 1e22 gave the fewest rounding errors.

Fix warnings from gcc. Some float constants do not behave well in existing tests.
Add casts where conversions could be imprecise.

Move double tests down in the file

Remove UNITY_FLOAT_VERBOSE entirely, add option UNITY_EXCLUDE_FLOAT_PRINT
Remove some questionable float casts from doubles
Default to Round Ties to Even behavior, add option to Round Ties Away from Zero