code style: whitespace, and using correct Class Definition
fix ReflectionCompletion not working inside brackets

The problem is that in order to find the instance
of the current context, the line start is not too helpful.

Example:
groovy:000> x = "3"
===> 3
groovy:000> String.toUpperCase(x.to<tab>

Before: no completion
After: toBigDecimal()   toBigInteger() ...
Keyword completion.
Hooked into global completion (start-of-line) for
visibility modifier and such

Hooked and into Reflection Completer for other keywords, as this may
happen anywhere in the line, and is similar enough.

Took some care to provide most probable spacing and some opening brackets.