update for 0.9.0
remove commas; fixes #137
remove/simplify some methods and validation logic; support for more schema options being functions that return dynamic values
don't filter out non-schema props from $unset object
add trimStrings option to clean, true by default; closes #140
add context.getErrorObject API function
fix #142
update docs and add `trim` option for schema defs
add test case
bump version