Merge branch 'update-preprocessor' into 'master'

relast.preprocessor

relast2uml.base/build.gradle

relast2uml.base/src/main/jastadd/Navigation.jrag

relast2uml.base/src/main/jastadd/scanner/Header.flex

relast2uml.base/src/main/jastadd/scanner/Keywords.flex

...c/main/java/org/jastadd/relast2uml/compiler/Compiler.java

.../org/jastadd/relast2uml/compiler/options/CommandLine.java

...a/org/jastadd/relast2uml/compiler/options/EnumOption.java

...a/org/jastadd/relast2uml/compiler/options/FlagOption.java

.../java/org/jastadd/relast2uml/compiler/options/Option.java

...org/jastadd/relast2uml/compiler/options/StringOption.java

...c/test/java/org/jastadd/relast2uml/test/CompilerTest.java