surface density, cropseg, hemi flag, fast laplace init

• new unfold templates with variable density
• included DG in template shape injection
• updated documentation
• Dice qc (#76)
• added cropseg modality type
• update input for shape inject, target rules
• added space wildcard for giftis
• allow autotop to run with no initialization
• added --hemi option
• fix nan vertices in output surfaces (#90)
• fast laplace via initialization (#88)