Brought get_taxa up to Google's R style guide.
Brought write_agefile and compile_taxa up to Google's R Style guide standards. Made minor syle guide improvements that I missed the first time around in several other files. Also changed get_datasets to get_dataset in several examples. Ran most of the examples and they seem to be working fine.
Merge pull request #5 from sosalla/master

Brought write_agefile and compile_taxa up to Google's R Style guide standards.