Merge pull request #10 from PiTiLeZarD/master

bufferSize and english
Merge pull request #11 from PiTiLeZarD/master

fix mysql varchar limit
mETL 0.1.6.11 Fields has a new limit attribute for database targets. Easy to add new database types if necessary. Complex, List types tests are added.
mETL 0.1.6.12 Boolean conversion is working for String correctly.
Added elseClean option to MapTransform
Modify the dependencies: xml2dict package renamed to xmlsquash
Source clone method, AppendExpand works for all sources and have the opportunity to skip sources when failing with friendly logging. HTTPResponse error fixed.
Documentation update for new attributes
mETL 0.1.6.13 Added JoinByKey modifier to easily join two sources and fill out some fields.
Grammar fix
mETL 0.1.6.14 Added metl-generate command to generate automatically Yaml configuration files.
Minor fix for SplitTransform and FieldMap for empty selections.
have a primary key in case we take it from a file