- Bug fixed replacing the special chars when calculating the visible variables.
- Added the two Boolean literals "true" and "false" to the completion items.
- Implemented the auto-completion case when the cursor is right after the following expression: <expression-head prefix-or-infix-operator accumulated-text>. In that case, all OCL variables and literals of type the type of the prefix-or-infix-operator, in addition to the set of prefix operations which source type is the type of the prefix-or-infix-operator, are listed at the beginning of the list, while the rest of elements that do not match with the type are listed after.