Support numerals the way JSON spec defines them

[kosty]

Currently TypeValidator has a loose mode (which is great) but isInteger and isNumeric do not fully comply with numeric literals defined by JSON spec. In particular the following values are not regarded as numbers by JSON (some of them are successfully validated by TypeValidator)

"01.1", "1.", ".1", "E1", "E+1", "E-1", ".E1", ".E+1", ".E-1", ".1E1", ".1E+1", ".1E-1", "+1"

also the following values are all valid numbers as per spec

"1", "-1", "1.1", "-1.1", "0E+1", "0E-1", "0E1", "-0E+1", "-0E-1", "-0E1", "0.1E+1", "0.1E-1", "0.1E1", "-0.1E+1", "-0.1E-1", "-0.1E1", "10.1", "-10.1", "10E+1", "10E-1", "10E1", "-10E+1", "-10E-1", "-10E1", "10.1E+1", "10.1E-1", "10.1E1", "-10.1E+1", "-10.1E-1", "-10.1E1" 

Note
+1, 0001 is currently successfully validated by TypeValidator adhering to spec might introduce breaking change for some of existing users

[kosty]

@stevehu please treat this PR as a proposal/starting point. Let's figure out which direction to take it.

[stevehu]

For sure. I have already invited other members who are familiar with the project to review. We can discuss in the PR. I am glad that you have included unit tests to make the usage very clear. Thanks.

[kosty]

Just realized, this was not closed after merge. Closing