Merge pull request rsim#107 from rsim/release/0.6.0

Release 0.6.0

Release 0.5.3

Merge pull request rsim#70 from rsim/release-0.5.2

Release 0.5.2

Merge pull request rsim#67 from rsim/release-0.5.1

Release 0.5.1

described changes for version 0.5.0

description of version 0.4.4

description of version 0.4.3

do not use methods of core classes that are defined by Rails

fixed usage examples in insert_values description comments

updated RDoc documentation for methods