Json parser

See merge request !92

- fixed some unit tests (updated some error messages, commented out some obselete tests)

- re-enabled all of the roundtrip*.json tests

- changed handling of parse errors to use boolean returns instead of using is_null() since using the later causes "null" literals to fail
- fixed a few parser bugs found by unit tests
- fixed a bug in unit test code causing false negatives
- now allowing one trailing comma in arrays and objects

Fortify changes.

See merge request !90

Some compilers allow overrun of string format specifier. HysplitCDumpStream...

See merge request !91

Some compilers allow overrun of string format specifier. HysplitCDumpStream had two such occurances that would present as stack smashing.

Update array indices to prevent out of bounds.

See merge request !88

Numpad sign

See merge request !87