Integrate parser from MojNumber into MojDecimal

:Release Notes:
Integrated new parser for numbers into DB8.

:Detailed Notes:
- convert parser from C++11
- replace old parser inside method MojDecimal::assign(const MojChar*)
  with a call to a new one.
- fixed tests:
    - DecimalTest.parse_with_rounding
    - DecimalTest.parse_unbalanced_small
    - DecimalTest.parse_unbalanced_big
    - DecimalTest.parse_overflow_mantissa
    - DecimalTest.parse_overflow_exponent
    - DecimalTest.parse_overflow_exponent_bound

:Testing Performed:
test_core and test_mojocore

:QA Notes:

:Issues Addressed:
[GF-36958] MojDecimal in DB8 have issues with rounding and exponent

Open-webOS-DCO-1.0-Signed-off-by: Nikolay Orliuk <nikolay.orliuk@lge.com>

Change-Id: Iae239348f95390c5be2bfee08b293578060e6d3a
Reviewed-on: https://g2g.palm.com/3331
Reviewed-by: Build Verification
Reviewed-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Tested-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Reviewed-by: Roger Stringer <roger.stringer@lge.com>