Delete clang flags that were disabled with -Wno-*

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

Delete warning flags included by -Wall, -Wextra, or produce false postives

This resolves #219. When generating a new module, if all the files to
generate already exist then it fails as before. If some of the files
already exist, then the files that need to be created are created. Any
existing files are not changed.

Also added a bunch of tests for this feature via rspec. Run them from
the test folder with `rake spec`.

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

Linux gcc & clang and OSX clang produce output with ties round to even
Windows mingw gcc does not
Example 0.0078125 prints '0.007812'

Finished fixing floating point comparisons. We have streamlined how floats and doubles are checked, but we still can't compare them for equality directly. So we're directly testing for infinite and NaN before checking diffs. Also, we've officially decided that for testing purposes NaN shall equal NaN, +Inf shall equal +Inf, and -Inf shall equal -Inf. It's what most people expect during a test.

Add check for linux and move initial CFLAG settings inside linux check. Add
CFLAGS specific to osx and clang to the existing osx/darwin check. Ignore clang warning about default on covered enum switch, look at pull #217 and pull #177 for more info about why that warning is ignored on clang. Ignore unknown clang options so that I don't have to change CFLAG settings elsewhere in the file, clang should just ignore options it dosen't know about.

 Changes from "\0x16" before, makes it easier to copy strings from output

 Works when using the putcharSpy, transparent without it

 Refactor to use the same code everywhere for FloatWithin check
 Rename and fix a few tests for new behavior, infinity == infinity

 CC always exists inside make so ?= doesn't assign to it

 The C preprocessor cannot use sizeof in #if etc.

 Covers the cases where infinity == infinity