DSL parsing/expansion: '\', '$', empty value, empty condition

DSL parser does not accept an empty "value" section, e.g.
[when] a man loves a woman=

Expansion of a rule with an empty condition results in "whenthen".

The DSL parser escapes '$', but not '\' in value sections. It should not modify the value section except for "normalizing" variable references. Variable references should be restricted to a "clean" character sequence (e.g. Java identifier). The current expansion using replaceAll is too fragile.

I have emailed three reworked source files AntlrDSLMappingEntry.java DefaultExpander.java DSLTokenizedMappingFile.java to Edson, but I didn't change the parser itself.