Default parsers

[cknv]

This adds a few functions to help parse some datatypes. This is just suppose to make it less needed to have lambdas all over the place and reducing the need of tiresome redundancy.

• boolean function
• split by comma

Find the right name for the module with the functions. helpers seems ok, but as it is already in use, it requires some moving around.

[coveralls]

Coverage remained the same at 100.0% when pulling 9fe8003 on default-parsers into 26df9cc on master.

[coveralls]

Coverage remained the same at 100.0% when pulling 95a0265 on default-parsers into 26df9cc on master.

[coveralls]

Coverage remained the same at 100.0% when pulling a629e40 on default-parsers into 26df9cc on master.