Fix shadow local variable warnings

This branch fixes the following warnings when loading parser:

```
/home/mbj/devel/parser/lib/parser/lexer.rb:14335: warning: shadowing outer local variable - value
/home/mbj/devel/parser/lib/parser/lexer.rb:14373: warning: shadowing outer local variable - value
/home/mbj/devel/parser/lib/parser/lexer.rb:14411: warning: shadowing outer local variable - value
/home/mbj/devel/parser/lib/parser/lexer.rb:17902: warning: shadowing outer local variable - value
/home/mbj/devel/parser/lib/parser/lexer.rb:19748: warning: shadowing outer local variable - value
/home/mbj/devel/parser/lib/parser/lexer.rb:19758: warning: shadowing outer local variable - value
/home/mbj/devel/parser/lib/parser/lexer.rb:19765: warning: shadowing outer local variable - value
/home/mbj/devel/parser/lib/parser/lexer.rb:20327: warning: shadowing outer local variable - value
/home/mbj/devel/parser/lib/parser/lexer.rb:20371: warning: shadowing outer local variable - value
/home/mbj/devel/parser/lib/parser/lexer.rb:20415: warning: shadowing outer local variable - value
/home/mbj/devel/parser/lib/parser/lexer.rb:20459: warning: shadowing outer local variable - value
/home/mbj/devel/parser/lib/parser/lexer.rb:20503: warning: shadowing outer local variable - value
/home/mbj/devel/parser/lib/parser/lexer.rb:20547: warning: shadowing outer local variable - value
/home/mbj/devel/parser/lib/parser/lexer.rb:20613: warning: shadowing outer local variable - value
/home/mbj/devel/parser/lib/parser/lexer.rb:20630: warning: shadowing outer local variable - value
/home/mbj/devel/parser/lib/parser/lexer.rb:20647: warning: shadowing outer local variable - value
```

The warnings can be reproduced via:

```
ruby -I lib -r parser/current -w -e ''
```


There is another (last) warning:

```
/home/mbj/devel/parser/lib/parser/lexer.rb:10616: warning: assigned but unused variable - testEof
```

This one needs to be fixed in the ragel code emitter.