Compiler tasks that have the same output file are grouped and their sources concatenated; data
sources are concatenated directly, file sources are concatenated as sass import statements. Also,
removed source from setSourceMap callback to keep in sync with outFile and because source can also be a data string.
Compiler tasks that have the same output file are grouped and their sources concatenated; data sources are concatenated directly, file sources are concatenated as sass import statements. Also, removed source from setSourceMap callback to keep in sync with outFile and because source can also be a data string.
closes #19