release draft to master (#19)

* StringCollection: +Natural docs comments
+ minor code cleanup

* BuildCriteria: +SplitToArray with (and/or)

* Export/Reimport script for MZ-Tools

* minor optimizations

* + CalculationTextBox.cls

* CalculationTextBox: allow = at first position of existing value in textbox

* CalculationTextBox: + Events, Undo/Cancel

* SqlTools, FilterStringBuilder: Add function SelectDialect
   SqlTools.SelectDialect(SQL_DAO) .. short form: SqlTools(SQL_DAO)

* SqlTools: minor refactoring (use FromDialect instead SelectDialect, add InitSqlDialect)

* + [WhereStatement] replacement feature for AddExistsCriteria

* FilterControlCollection: remove initial test debug output

* FilterStringBuilder: add property to retrieve WHERE replacement text placeholder

Merge pull request #14 from AccessCodeLib/draft

SqlTools.ConvertToNumeric refactored

Draft (#7)

* DbConnectionInfo: refactoring

* Change interface comments to Natural Docs syntax

* replace doxygen comments with Natural Docs comments

German comments => English