Add test case
Merge branch 'master' into issue120floatprecision
Fallback strtod() when not able to do fast-path

This shall generate best possible precision (if strtod() is correctly
implemented). Need more unit tests and performance tests. May add an
option for accepting precision error. Otherwise LUT in Pow10() can be
reduced.
Add random tests for ParseNumber
Check "fast path cases in disguise" in strtod
Refactor ParseNumber for two modes (incomplete)
Merge master and implement kParseFullPrecision
Optimize ParseNumber()
Fix ParseNumber_Integer test
Compute error statistics of normal precision
Update document for kParseFullPrecisionFlag
Fix VC2010 which don't have std::isnan() et al.
Prepare custom strtod data. (cannot pass unit test) [ci skip]
Extract conversion code to strtod.h [ci skip]
Implementing custom strtod, fail on some cases [ci skip]
Make custom strtod work for denormal numbers and some boundary cases [ci skip]
Makes gcc x64 runnable, but failed on one case. [ci skip]
Add 32-bit support for custom strtod
Fix a unit test warning and suppress a failing case
Fix normal-subnormal boundary and add more boundary cases in unit tests.