Improved build scripts (.bat).
Captions generator and improved MVC model attributes (contributions by iprlic and GADMarko)
* Implemented `Captions.resx` resource file generator with plugins for data structures, properties and CamelCase splitter.
* MVC model namespace changed from <modulename> to Rhetos.Mvc.<modulename> to avoid client namespace overlapping.
* Fixed formatting of Date, Decimal and LongString.
* Added constants for entity and property names.
* New MVC model attributes: LocalizedDisplayNameAttribute, RenderModeAttribute.
* GUI behavior heuristics: default values for AutoCode and Active bool, hiding *ID fields in edit or view mode.

Internal improvements:
* OverridableAttribute helper for generating the source code with attributes that have AllowMultiple = false.
* Fixed implementation of multiple constraint by using only a single most limiting constraint, for concepts: MaxLength, MinLength, MaxValue, MinValue, Required.
Release 1.4.