Merge pull request #1 from sgiavasis/0.3.4_development

0.3.4 development
Added single-core run for ANTs process
Fixed the pipeline configuration file naming format to allow for both numbers and/or strings
Deleted duplicate function using BBRegister
Re-delted duplicate function using BBRegister
Merge branch '0.3.4_development' of https://github.com/dclark87/C-PAC into dcDev