Converting core.sequence to use slf4j instead of println #155
Converted all core.sequence.io print and printStackTrace to slf4j #155
Converted core.sequence.loader package from print and printStackTrace
and native logger to slf4j #155
Fixed logging issue with updated slf4j #155
Convert core.util package to use slf4j
Convert core src/test/java to slf4j #155
Merge pull request #166 from benjamintboyle/master

Convert core package to use slf4j #155