Add default value support to base language. #28

.../base/dsl/ide/contentassist/antlr/BaseLanguageParser.java

...l/ide/contentassist/antlr/internal/InternalBaseLanguage.g

.../contentassist/antlr/internal/InternalBaseLanguage.tokens

...ntentassist/antlr/internal/InternalBaseLanguageLexer.java

...tentassist/antlr/internal/InternalBaseLanguageParser.java

...i/contentassist/AbstractBaseLanguageProposalProvider.java

...n/de/evoal/languages/model/base/dsl/BaseLanguage.xtextbin

...del/base/dsl/parser/antlr/internal/InternalBaseLanguage.g

...ase/dsl/parser/antlr/internal/InternalBaseLanguage.tokens

.../dsl/parser/antlr/internal/InternalBaseLanguageLexer.java

...dsl/parser/antlr/internal/InternalBaseLanguageParser.java

...el/base/dsl/serializer/BaseLanguageSemanticSequencer.java

...es/model/base/dsl/services/BaseLanguageGrammarAccess.java

.../src/de/evoal/languages/model/base/dsl/BaseLanguage.xtext

...languages/de.evoal.languages.model.base/model/model.ecore

...guages/de.evoal.languages.model.base/model/model.genmodel

...en/de/evoal/languages/model/base/AttributeDefinition.java

...se/src-gen/de/evoal/languages/model/base/BasePackage.java

...al/languages/model/base/impl/AttributeDefinitionImpl.java

...n/de/evoal/languages/model/base/impl/BasePackageImpl.java