Fix docs.

- fixed ANSI (C89) issues, including #418

Fixed a simple mistake.

Added new CMakeLists.txt here in the src dir, moved add library method from root script to sub script.

Removed 'unity_src' variable because Unity only one source file, changed library method to static only because there was some issues with using Unity as a shared library, cleaned sub meson.build script and fixed comment in sub source root.

Get the 2's compliment of the unsigned int `number` when printing results without relying on problematic recasting of a negated int. (see #439)

* This can save a lot of program memory and allow to run test on ATTiny

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

- Tweak a couple style problems with Ruby scripts.

Introduce patch from "UnityAssertEqualIntArray" for "UnityAssertNumbersArrayWithin" in order to get rid of the sizeof() operator

sizeof() is a hell of an operator and returns the size of a data type in terms of "addressable units" which is not necessarily the size in bytes. To circumvent this problem and in order to keep the API clean we try to remove all sizeof() from the API.

Used sizeof() operator for pointer increments and substituted sizeof() operator for the unsigned int mask calculation to "UNITY_INT_WIDTH / 8" in function "UnityAssertEqualIntArray".

Fixed maximum number of nibbles for processor where sizeof() operator doesn't return the size of a type in 8-bit bytes (e.g. the TI C2000 series).

- 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

Avoid declaring the loop variable inside the for statement to keep
compatibility with c90:

unity.c:1408: error: for' loop initial declaration used outside C99 mode

Macro UNITY_EXCLUDE_PRINT_FORMATTED changed to UNITY_INCLUDE_PRINT_FORMATTED.
Enable printf via "-DUNITY_INCLUDE_PRINT_FORMATTED" compiler option.

Negating the most-negative signed integer results in overflow, which
is undefined behavior.  Fix this by casting to an unsigned type first
(unsigned overflow is well-defined as it uses modular arithmetic).

Added include of 'stddef.h' to 'unity_internals.h' if 'UNITY_EXCLUDE_STDDEF_H' is not defined. This adds compiler independent support for the 'NULL' macro.