add parser methods to all MonetaryAmounts implementations
using MonetaryAmountFormat
Added coveralls config.
Updated coverage setup.
Fix Compiler Warnings

The project contains several compiler warnings.

 * remove unused imports
 * remove unused methods
Fix a Typo ConvertBigDecimal#DEFAULT

Fix a typo in `org.javamoney.moneta.spi.ConvertBigDecimal#DEFAULT`.
use correct assert method